Congenital abnormalities, such as horseshoe kidney, are fairly common and usually harmless. Serious inherited disorders include polycystic kidney disease (see kidney, polycystic), Fanconi’s syndrome, and renal tubular acidosis.
Blood vessels in the kidneys can be damaged by shock, haemolytic–uraemic syndrome, polyarteritis nodosa, diabetes mellitus, and systemic lupus erythematosus. The filtering units may be inflamed (see glomerulonephritis). Allergic reactions to drugs, prolonged treatment with analgesic drugs, and some antibiotics can damage kidney tubules. Noncancerous kidney tumours are rare, as is kidney cancer. Metabolic disorders, such as hyperuricaemia, may cause kidney stones (see calculus, urinary tract). Infection of the kidney is called pyelonephritis. Hydronephrosis is caused by urinary tract obstruction. In crush syndrome, kidney function is disrupted by proteins released into the blood from damaged muscle. Hypertension can be a cause and an effect of kidney damage. The most obvious symptom of acute kidney failure is usually oliguria (reduced volume of urine). This leads to a build-up of urea and other waste products in the blood and tissues, which may cause drowsiness, nausea, and breathlessness. Symptoms of chronic kidney failure develop more gradually and may include nausea, loss of appetite, and weakness. If acute kidney failure is due to sudden reduction in blood flow, blood volume and pressure can be brought back to normal by saline intravenous infusion or blood transfusion. Surgery may be needed to remove an obstruction in the urinary tract. Acute kidney disease may be treated with corticosteroid drugs. Treatment may also involve diuretic drugs and temporary dialysis (artificial purification of the blood). A high-carbohydrate, lowprotein diet with controlled fluid and salt intake is important for both types of kidney failure. Chronic kidney failure may progress over months or years towards end-stage kidney failure, which is life-threatening. At this stage, longterm dialysis or a kidney transplant is the only effective treatment.
Treatment Any major de?ciencies, such as thyroxin or insulin lack, should be corrected. The activity of the immune system should then be reduced. CORTICOSTEROIDS and, in more severe cases, strong immunosuppressant drugs – AZATHIOPRINE, CYCLOPHOSPHAMIDE or METHOTREXATE – should be administered. Treatment is di?cult because of the need to control the autoimmune condition without damaging the body’s ability to combat other diseases.... autoimmune disorders
Bone fractures These occur when there is a break in the continuity of the bone. This happens either as a result of violence or because the bone is unhealthy and unable to withstand normal stresses.
SIMPLE FRACTURES Fractures where the skin remains intact or merely grazed. COMPOUND FRACTURES have at least one wound which is in communication with the fracture, meaning that bacteria can enter the fracture site and cause infection. A compound fracture is also more serious than a simple fracture because there is greater potential for blood loss. Compound fractures usually need hospital admission, antibiotics and careful reduction of the fracture. Debridement (cleaning and excising dead tissue) in a sterile theatre may also be necessary.
The type of fracture depends on the force which has caused it. Direct violence occurs when an object hits the bone, often causing a transverse break – which means the break runs horizontally across the bone. Indirect violence occurs when a twisting injury to the ankle, for example, breaks the calf-bone (the tibia) higher up. The break may be more oblique. A fall on the outstretched hand may cause a break at the wrist, in the humerus or at the collar-bone depending on the force of impact and age of the person. FATIGUE FRACTURES These occur after the bone has been under recurrent stress. A typical example is the march fracture of the second toe, from which army recruits suffer after long marches. PATHOLOGICAL FRACTURES These occur in bone which is already diseased – for example, by osteoporosis (see below) in post-menopausal women. Such fractures are typically crush fractures of the vertebrae, fractures of the neck of the femur, and COLLES’ FRACTURE (of the wrist). Pathological fractures also occur in bone which has secondary-tumour deposits. GREENSTICK FRACTURES These occur in young children whose bones are soft and bend, rather than break, in response to stress. The bone tends to buckle on the side opposite to the force. Greenstick fractures heal quickly but still need any deformity corrected and plaster of Paris to maintain the correction. COMPLICATED FRACTURES These involve damage to important soft tissue such as nerves, blood vessels or internal organs. In these cases the soft-tissue damage needs as much attention as the fracture site. COMMINUTED FRACTURES A fracture with more than two fragments. It usually means that the injury was more violent and that there is more risk of damage to vessels and nerves. These fractures are unstable and take longer to unite. Rehabilitation tends to be protracted. DEPRESSED FRACTURES Most commonly found in skull fractures. A fragment of bone is forced inwards so that it lies lower than the level of the bone surrounding it. It may damage the brain beneath it.
HAIR-LINE FRACTURES These occur when the bone is broken but the force has not been severe enough to cause visible displacement. These fractures may be easily missed. Symptoms and signs The fracture site is usually painful, swollen and deformed. There is asymmetry of contour between limbs. The limb is held uselessly. If the fracture is in the upper
limb, the arm is usually supported by the patient; if it is in the lower limb then the patient is not able to bear weight on it. The limb may appear short because of muscle spasm.
Examination may reveal crepitus – a bony grating – at the fracture site. The diagnosis is con?rmed by radiography.
Treatment Healing of fractures (union) begins with the bruise around the fracture being resorbed and new bone-producing cells and blood vessels migrating into the area. Within a couple of days they form a bridge of primitive bone across the fracture. This is called callus.
The callus is replaced by woven bone which gradually matures as the new bone remodels itself. Treatment of fractures is designed to ensure that this process occurs with minimal residual deformity to the bone involved.
Treatment is initially to relieve pain and may involve temporary splinting of the fracture site. Reducing the fracture means restoring the bones to their normal position; this is particularly important at the site of joints where any small displacement may limit movement considerably.
with plaster of Paris. If closed traction does not work, then open reduction of the fracture may
be needed. This may involve ?xing the fracture with internal-?xation methods, using metal plates, wires or screws to hold the fracture site in a rigid position with the two ends closely opposed. This allows early mobilisation after fractures and speeds return to normal use.
External ?xators are usually metal devices applied to the outside of the limb to support the fracture site. They are useful in compound fractures where internal ?xators are at risk of becoming infected.
Consolidation of a fracture means that repair is complete. The time taken for this depends on the age of the patient, the bone and the type of fracture. A wrist fracture may take six weeks, a femoral fracture three to six months in an adult.
Complications of fractures are fairly common. In non-union, the fracture does not unite
– usually because there has been too much mobility around the fracture site. Treatment may involve internal ?xation (see above). Malunion means that the bone has healed with a persistent deformity and the adjacent joint may then develop early osteoarthritis.
Myositis ossi?cans may occur at the elbow after a fracture. A big mass of calci?ed material develops around the fracture site which restricts elbow movements. Late surgical removal (after 6–12 months) is recommended.
Fractured neck of FEMUR typically affects elderly women after a trivial injury. The bone is usually osteoporotic. The leg appears short and is rotated outwards. Usually the patient is unable to put any weight on the affected leg and is in extreme pain. The fractures are classi?ed according to where they occur:
subcapital where the neck joins the head of the femur.
intertrochanteric through the trochanter.
subtrochanteric transversely through the upper end of the femur (rare). Most of these fractures of the neck of femur
need ?xing by metal plates or hip replacements, as immobility in this age group has a mortality of nearly 100 per cent. Fractures of the femur shaft are usually the result of severe trauma such as a road accident. Treatment may be conservative or operative.
In fractures of the SPINAL COLUMN, mere damage to the bone – as in the case of the so-called compression fracture, in which there is no damage to the spinal cord – is not necessarily serious. If, however, the spinal cord is damaged, as in the so-called fracture dislocation, the accident may be a very serious one, the usual result being paralysis of the parts of the body below the level of the injury. Therefore the higher up the spine is fractured, the more serious the consequences. The injured person should not be moved until skilled assistance is at hand; or, if he or she must be removed, this should be done on a rigid shutter or door, not on a canvas stretcher or rug, and there should be no lifting which necessitates bending of the back. In such an injury an operation designed to remove a displaced piece of bone and free the spinal cord from pressure is often necessary and successful in relieving the paralysis. DISLOCATIONS or SUBLUXATION of the spine are not uncommon in certain sports, particularly rugby. Anyone who has had such an injury in the cervical spine (i.e. in the neck) should be strongly advised not to return to any form of body-contact or vehicular sport.
Simple ?ssured fractures and depressed fractures of the skull often follow blows or falls on the head, and may not be serious, though there is always a risk of damage which is potentially serious to the brain at the same time.
Compound fractures may result in infection within the skull, and if the skull is extensively broken and depressed, surgery is usually required to check any intercranial bleeding or to relieve pressure on the brain.
The lower jaw is often fractured by a blow on the face. There is generally bleeding from the mouth, the gum being torn. Also there are pain and grating sensations on chewing, and unevenness in the line of the teeth. The treatment is simple, the line of teeth in the upper jaw forming a splint against which the lower jaw is bound, with the mouth closed.
Congenital diseases These are rare but may produce certain types of dwar?sm or a susceptibility to fractures (osteogenesis imperfecta).
Infection of bone (osteomyelitis) may occur after an open fracture, or in newborn babies with SEPTICAEMIA. Once established it is very di?cult to eradicate. The bacteria appear capable of lying dormant in the bone and are not easily destroyed with antibiotics so that prolonged treatment is required, as might be surgical drainage, exploration or removal of dead bone. The infection may become chronic or recur.
Osteomalacia (rickets) is the loss of mineralisation of the bone rather than simple loss of bone mass. It is caused by vitamin D de?ciency and is probably the most important bone disease in the developing world. In sunlight the skin can synthesise vitamin D (see APPENDIX 5: VITAMINS), but normally rickets is caused by a poor diet, or by a failure to absorb food normally (malabsorbtion). In rare cases vitamin D cannot be converted to its active state due to the congenital lack of the speci?c enzymes and the rickets will fail to respond to treatment with vitamin D. Malfunction of the parathyroid gland or of the kidneys can disturb the dynamic equilibrium of calcium and phosphate in the body and severely deplete the bone of its stores of both calcium and phosphate.
Osteoporosis A metabolic bone disease resulting from low bone mass (osteopenia) due to excessive bone resorption. Su?erers are prone to bone fractures from relatively minor trauma. With bone densitometry it is now possible to determine individuals’ risk of osteoporosis and monitor their response to treatment.
By the age of 90 one in two women and one in six men are likely to sustain an osteoporosis-related fracture. The incidence of fractures is increasing more than would be expected from the ageing of the population, which may re?ect changing patterns of exercise or diet.
Osteoporosis may be classi?ed as primary or secondary. Primary consists of type 1 osteoporosis, due to accelerated trabecular bone loss, probably as a result of OESTROGENS de?ciency. This typically leads to crush fractures of vertebral bodies and fractures of the distal forearm in women in their 60s and 70s. Type 2 osteoporosis, by contrast, results from the slower age-related cortical and travecular bone loss that occurs in both sexes. It typically leads to fractures of the proximal femur in elderly people.
Secondary osteoporosis accounts for about 20 per cent of cases in women and 40 per cent of cases in men. Subgroups include endocrine (thyrotoxicosis – see under THYROID GLAND, DISEASES OF, primary HYPERPARATHYROIDISM, CUSHING’S SYNDROME and HYPOGONADISM); gastrointestinal (malabsorption syndrome, e.g. COELIAC DISEASE, or liver disease, e.g. primary biliary CIRRHOSIS); rheumatological (RHEUMATOID ARTHRITIS or ANKYLOSING SPONDYLITIS); malignancy (multiple MYELOMA or metastatic CARCINOMA); and drugs (CORTICOSTEROIDS, HEPARIN). Additional risk factors for osteoporosis include smoking, high alcohol intake, physical inactivity, thin body-type and heredity.
Individuals at risk of osteopenia, or with an osteoporosis-related fracture, need investigation with spinal radiography and bone densitometry. A small fall in bone density results in a large increase in the risk of fracture, which has important implications for preventing and treating osteoporosis.
Treatment Antiresorptive drugs: hormone replacement therapy – also valuable in treating menopausal symptoms; treatment for at least ?ve years is necessary, and prolonged use may increase risk of breast cancer. Cyclical oral administration of disodium etidronate – one of the bisphosphonate group of drugs – with calcium carbonate is also used (poor absorption means the etidronate must be taken on an empty stomach). Calcitonin – currently available as a subcutaneous injection; a nasal preparation with better tolerance is being developed. Calcium (1,000 mg daily) seems useful in older patients, although probably ine?ective in perimenopausal women, and it is a safe preparation. Vitamin D and calcium – recent evidence suggests value for elderly patients. Anabolic steroids, though androgenic side-effects (masculinisation) make these unacceptable for most women.
With established osteoporosis, the aim of treatment is to relieve pain (with analgesics and physical measures, e.g. lumbar support) and reduce the risk of further fractures: improvement of bone mass, the prevention of falls, and general physiotherapy, encouraging a healthier lifestyle with more daily exercise.
Further information is available from the National Osteoporosis Society.
Paget’s disease (see also separate entry) is a common disease of bone in the elderly, caused by overactivity of the osteoclasts (cells concerned with removal of old bone, before new bone is laid down by osteoblasts). The bone affected thickens and bows and may become painful. Treatment with calcitonin and bisphosphonates may slow down the osteoclasts, and so hinder the course of the disease, but there is no cure.
If bone loses its blood supply (avascular necrosis) it eventually fractures or collapses. If the blood supply does not return, bone’s normal capacity for healing is severely impaired.
For the following diseases see separate articles: RICKETS; ACROMEGALY; OSTEOMALACIA; OSTEOGENESIS IMPERFECTA.
Tumours of bone These can be benign (non-cancerous) or malignant (cancerous). Primary bone tumours are rare, but secondaries from carcinoma of the breast, prostate and kidneys are relatively common. They may form cavities in a bone, weakening it until it breaks under normal load (a pathological fracture). The bone eroded away by the tumour may also cause problems by causing high levels of calcium in the plasma.
EWING’S TUMOUR is a malignant growth affecting long bones, particularly the tibia (calfbone). The presenting symptoms are a throbbing pain in the limb and a high temperature. Treatment is combined surgery, radiotherapy and chemotherapy.
MYELOMA is a generalised malignant disease of blood cells which produces tumours in bones which have red bone marrow, such as the skull and trunk bones. These tumours can cause pathological fractures.
OSTEOID OSTEOMA is a harmless small growth which can occur in any bone. Its pain is typically removed by aspirin.
OSTEOSARCOMA is a malignant tumour of bone with a peak incidence between the ages of ten and 20. It typically involves the knees, causing a warm tender swelling. Removal of the growth with bone conservation techniques can often replace amputation as the de?nitive treatment. Chemotherapy can improve long-term survival.... bone, disorders of
Astigmatism (See ASTIGMATISM.)
Blepharitis A chronic in?ammation of the lid margins. SEBORRHOEA and staphylococcal infection are likely contributors. The eyes are typically intermittently red, sore and gritty over months or years. Treatment is di?cult and may fail. Measures to reduce debris on the lid margins, intermittent courses of topical antibiotics, steroids or systemic antibiotics may help the sufferer.
Blepharospasm Involuntary closure of the eye. This may accompany irritation but may also occur without an apparent cause. It may be severe enough to interfere with vision. Treatment involves removing the source of irritation, if present. Severe and persistent cases may respond to injection of Botulinum toxin into the orbicularis muscle.
Cataract A term used to describe any opacity in the lens of the eye, from the smallest spot to total opaqueness. The prevalence of cataracts is age-related: 65 per cent of individuals in their sixth decade have some degree of lens opacity, while all those over 80 are affected. Cataracts are the most important cause of blindness worldwide. Symptoms will depend on whether one or both eyes are affected, as well as the position and density of the cataract(s). If only one eye is developing a cataract, it may be some time before the person notices it, though reading may be affected. Some people with cataracts become shortsighted, which in older people may paradoxically ‘improve’ their ability to read. Bright light may worsen vision in those with cataracts.
The extent of visual impairment depends on the nature of the cataracts, and the ?rst symptoms noticed by patients include di?culty in recognising faces and in reading, while problems watching television or driving, especially at night, are pointers to the condition. Cataracts are common but are not the only cause of deteriorating vision. Patients with cataracts should be able to point to the position of a light and their pupillary reactions should be normal. If a bright light is shone on the eye, the lens may appear brown or, in advanced cataracts, white (see diagram).
While increasing age is the commonest cause of cataract in the UK, patients with DIABETES MELLITUS, UVEITIS and a history of injury to the eye can also develop the disorder. Prolonged STEROID treatment can result in cataracts. Children may develop cataracts, and in them the condition is much more serious as vision may be irreversibly impaired because development of the brain’s ability to interpret visual signals is hindered. This may happen even if the cataracts are removed, so early referral for treatment is essential. One of the physical signs which doctors look for when they suspect cataract in adults as well as in children is the ‘red re?ex’. This is observable when an ophthalmoscopic examination of the eye is made (see OPHTHALMOSCOPE). Identi?cation of this red re?ex (a re?ection of light from the red surface of the retina –see EYE) is a key diagnostic sign in children, especially young ones.
There is no e?ective medical treatment for established cataracts. Surgery is necessary and the decision when to operate depends mainly on how the cataract(s) affect(s) the patient’s vision. Nowadays, surgery can be done at any time with limited risk. Most patients with a vision of 6/18 – 6/10 is the minimum standard for driving – or worse in both eyes should
E
bene?t from surgery, though elderly people may tolerate visual acuity of 6/18 or worse, so surgery must be tailored to the individual’s needs. Younger people with a cataract will have more demanding visual requirements and so may opt for an ‘earlier’ operation. Most cataract surgery in Britain is now done under local anaesthetic and uses the ‘phaco-emulsi?cation’ method. A small hole is made in the anterior capsule of the lens after which the hard lens nucleus is liqui?ed ultrasonically. A replacement lens is inserted into the empty lens bag (see diagram). Patients usually return to their normal activities within a few days of the operation. A recent development under test in the USA for children requiring cataract operations is an intra-ocular ?exible implant whose magnifying power can be altered as a child develops, thus precluding the need for a series of corrective operations as happens now.
Chalazion A ?rm lump in the eyelid relating to a blocked meibomian gland, felt deep within the lid. Treatment is not always necessary; a proportion spontaneously resolve. There can be associated infection when the lid becomes red and painful requiring antibiotic treatment. If troublesome, the chalazion can be incised under local anaesthetic.
Conjunctivitis In?ammation of the conjunctiva (see EYE) which may affect one or both eyes. Typically the eye is red, itchy, sticky and gritty but is not usually painful. Redness is not always present. Conjunctivitis can occasionally be painful, particularly if there is an associated keratitis (see below) – for example, adenovirus infection, herpetic infection.
The cause can be infective (bacteria, viruses or CHLAMYDIA), chemical (e.g. acids, alkalis) or allergic (e.g. in hay fever). Conjunctivitis may also be caused by contact lenses, and preservatives or even the drugs in eye drops may cause conjunctival in?ammation. Conjunctivitis may addtionally occur in association with other illnesses – for example, upper-respiratory-tract infection, Stevens-Johnson syndrome (see ERYTHEMA – erythema multiforme) or REITER’S SYNDROME. The treatment depends on the cause. In many patients acute conjunctivitis is self-limiting.
Dacryocystitis In?ammation of the lacrimal sac. This may present acutely as a red, painful swelling between the nose and the lower lid. An abscess may form which points through the skin and which may need to be drained by incision. Systemic antibiotics may be necessary. Chronic dacryocystitis may occur with recurrent discharge from the openings of the tear ducts and recurrent swelling of the lacrimal sac. Obstruction of the tear duct is accompanied by watering of the eye. If the symptoms are troublesome, the patient’s tear passageways need to be surgically reconstructed.
Ectropion The lid margin is everted – usually the lower lid. Ectropion is most commonly associated with ageing, when the tissues of the lid become lax. It can also be caused by shortening of the skin of the lids such as happens with scarring or mechanical factors – for example, a tumour pulling the skin of the lower lid downwards. Ectropion tends to cause watering and an unsightly appearance. The treatment is surgical.
Entropion The lid margin is inverted – usually the lower lid. Entropion is most commonly associated with ageing, when the tissues of the lid become lax. It can also be caused by shortening of the inner surfaces of the lids due to scarring – for example, TRACHOMA or chemical burns. The inwardly directed lashes cause irritation and can abrade the cornea. The treatment is surgical.
Episcleritis In?ammation of the EPISCLERA. There is usually no apparent cause. The in?ammation may be di?use or localised and may affect one or both eyes. It sometimes recurs. The affected area is usually red and moderately painful. Episcleritis is generally not thought to be as painful as scleritis and does not lead to the same complications. Treatment is generally directed at improving the patient’s symptoms. The in?ammation may respond to NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS) or topical CORTICOSTEROIDS.
Errors of refraction (Ametropia.) These will occur when the focusing power of the lens and cornea does not match the length of the eye, so that rays of light parallel to the visual axis are not focused at the fovea centralis (see EYE). There are three types of refractive error: HYPERMETROPIA or long-sightedness. The refractive power of the eye is too weak, or the eye is too short so that rays of light are brought to a focus at a point behind the retina. Longsighted people can see well in the distance but generally require glasses with convex lenses for reading. Uncorrected long sight can lead to headaches and intermittent blurring of vision following prolonged close work (i.e. eye strain). As a result of ageing, the eye becomes gradually long-sighted, resulting in many people needing reading glasses in later life: this normal process is known as presbyopia. A particular form of long-sightedness occurs after cataract extraction (see above). MYOPIA(Short sight or near sight.) Rays of light are brought to a focus in front of the retina because the refractive power of the eye is too great or the eye is too short. Short-sighted people can see close to but need spectacles with concave lenses in order to see in the distance. ASTIGMATISMThe refractive power of the eye is not the same in each meridian. Some rays of light may be focused in front of the retina while others are focused on or behind the retina. Astigmatism can accompany hypermetropia or myopia. It may be corrected by cylindrical lenses: these consist of a slice from the side of a cylinder (i.e. curved in one meridian and ?at in the meridian at right-angles to it).
Keratitis In?ammation of the cornea in response to a variety of insults – viral, bacterial, chemical, radiation, or mechanical trauma. Keratitis may be super?cial or involve the deeper layers, the latter being generally more serious. The eye is usually red, painful and photophobic. Treatment is directed at the cause.
Nystagmus Involuntary rhythmic oscillation of one or both eyes. There are several causes including nervous disorders, vestibular disorders, eye disorders and certain drugs including alcohol.
Ophthalmia In?ammation of the eye, especially the conjunctiva (see conjunctivitis, above). Ophthalmia neonatorum is a type of conjunctivitis that occurs in newborn babies. They catch the disease when passing through an infected birth canal during their mother’s labour (see PREGNANCY AND LABOUR). CHLAMYDIA and GONORRHOEA are the two most common infections. Treatment is e?ective with antibiotics: untreated, the infection may cause permanent eye damage.
Pinguecula A benign degenerative change in the connective tissue at the nasal or temporal limbus (see EYE). This is visible as a small, ?attened, yellow-white lump adjacent to the cornea.
Pterygium Overgrowth of the conjunctival tissues at the limbus on to the cornea (see EYE). This usually occurs on the nasal side and is associated with exposure to sunlight. The pterygium is surgically removed for cosmetic reasons or if it is thought to be advancing towards the visual axis.
Ptosis Drooping of the upper lid. May occur because of a defect in the muscles which raise the lid (levator complex), sometimes the result of ageing or trauma. Other causes include HORNER’S SYNDROME, third cranial nerve PALSY, MYASTHENIA GRAVIS, and DYSTROPHIA MYOTONICA. The cause needs to be determined and treated if possible. The treatment for a severely drooping lid is surgical, but other measures can be used to prop up the lid with varying success.
Retina, disorders of The retina can be damaged by disease that affects the retina alone, or by diseases affecting the whole body.
Retinopathy is a term used to denote an abnormality of the retina without specifying a cause. Some retinal disorders are discussed below. DIABETIC RETINOPATHY Retinal disease occurring in patients with DIABETES MELLITUS. It is the commonest cause of blind registration in Great Britain of people between the ages of 20 and 65. Diabetic retinopathy can be divided into several types. The two main causes of blindness are those that follow: ?rst, development of new blood vessels from the retina, with resultant complications and, second, those following ‘water logging’ (oedema) of the macula. Treatment is by maintaining rigid control of blood-sugar levels combined with laser treatment for certain forms of the disease – in particular to get rid of new blood vessels. HYPERTENSIVE RETINOPATHY Retinal disease secondary to the development of high blood pressure. Treatment involves control of the blood pressure (see HYPERTENSION). SICKLE CELL RETINOPATHY People with sickle cell disease (see under ANAEYIA) can develop a number of retinal problems including new blood vessels from the retina. RETINOPATHY OF PREMATURITY (ROP) Previously called retrolental ?broplasia (RLF), this is a disorder affecting low-birth-weight premature babies exposed to oxygen. Essentially, new blood vessels develop which cause extensive traction on the retina with resultant retinal detachment and poor vision. RETINAL ARTERY OCCLUSION; RETINAL VEIN OCCLUSION These result in damage to those areas of retina supplied by the affected blood vessel: the blood vessels become blocked. If the peripheral retina is damaged the patient may be completely symptom-free, although areas of blindness may be detected on examination of ?eld of vision. If the macula is involved, visual loss may be sudden, profound and permanent. There is no e?ective treatment once visual loss has occurred. SENILE MACULAR DEGENERATION (‘Senile’ indicates age of onset and has no bearing on mental state.) This is the leading cause of blindness in the elderly in the western world. The average age of onset is 65 years. Patients initially notice a disturbance of their vision which gradually progresses over months or years. They lose the ability to recognise ?ne detail; for example, they cannot read ?ne print, sew, or recognise people’s faces. They always retain the ability to recognise large objects such as doors and chairs, and are therefore able to get around and about reasonably well. There is no e?ective treatment in the majority of cases. RETINITIS PIGMENTOSAA group of rare, inherited diseases characterised by the development of night blindness and tunnel vision. Symptoms start in childhood and are progressive. Many patients retain good visual acuity, although their peripheral vision is limited. One of the characteristic ?ndings on examination is collections of pigment in the retina which have a characteristic shape and are therefore known as ‘bone spicules’. There is no e?ective treatment. RETINAL DETACHMENTusually occurs due to the development of a hole in the retina. Holes can occur as a result of degeneration of the retina, traction on the retina by the vitreous, or injury. Fluid from the vitreous passes through the hole causing a split within the retina; the inner part of the retina becomes detached from the outer part, the latter remaining in contact with the choroid. Detached retina loses its ability to detect light, with consequent impairment of vision. Retinal detachments are more common in the short-sighted, in the elderly or following cataract extraction. Symptoms include spots before the eyes (?oaters), ?ashing lights and a shadow over the eye with progressive loss of vision. Treatment by laser is very e?ective if caught early, at the stage when a hole has developed in the retina but before the retina has become detached. The edges of the hole can be ‘spot welded’ to the underlying choroid. Once a detachment has occurred, laser therapy cannot be used; the retina has to be repositioned. This is usually done by indenting the wall of the eye from the outside to meet the retina, then making the retina stick to the wall of the eye by inducing in?ammation in the wall (by freezing it). The outcome of surgery depends largely on the extent of the detachment and its duration. Complicated forms of detachment can occur due to diabetic eye disease, injury or tumour. Each requires a specialised form of treatment.
Scleritis In?ammation of the sclera (see EYE). This can be localised or di?use, can affect the anterior or the posterior sclera, and can affect one or both eyes. The affected eye is usually red and painful. Scleritis can lead to thinning and even perforation of the sclera, sometimes with little sign of in?ammation. Posterior scleritis in particular may cause impaired vision and require emergency treatment. There is often no apparent cause, but there are some associated conditions – for example, RHEUMATOID ARTHRITIS, GOUT, and an autoimmune disease affecting the nasal passages and lungs called Wegener’s granulomatosis. Treatment depends on severity but may involve NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS), topical CORTICOSTEROIDS or systemic immunosuppressive drugs.
Stye Infection of a lash follicle. This presents as a painful small red lump at the lid margin. It often resolves spontaneously but may require antibiotic treatment if it persists or recurs.
Sub-conjunctival haemorrhage Haemorrhage between the conjunctiva and the underlying episclera. It is painless. There is usually no apparent cause and it resolves spontaneously.
Trichiasis Inward misdirection of the lashes. Trichiasis occurs due to in?ammation of or trauma to the lid margin. Treatment involves removal of the patient’s lashes. Regrowth may be prevented by electrolysis, by CRYOTHERAPY to the lid margin, or by surgery.
For the subject of arti?cial eyes, see under PROSTHESIS; also GLAUCOMA, SQUINT and UVEITIS.... eye, disorders of
Laryngitis In?ammation of the mucous membrane of the larynx and vocal chords may be acute or chronic. The cause is usually an infection, most commonly viral, although it may be the result of secondary bacterial infection, voice abuse or irritation by gases or chemicals. ACUTE LARYNGITIS may accompany any form of upper-respiratory-tract infection. The main symptom is hoarseness and often pain in the throat. The voice becomes husky or it may be lost. Cough, breathing diffculties and sometimes stridor may occur. Acute airway obstruction is unusual following laryngitis but may occasionally occur in infants (see laryngotracheo-bronchitis, below).
Treatment Vapour inhalations may be soothing and reduce swelling. Usually all that is needed is rest and analgesics such as paracetamol. Rarely, airway intervention – either ENDOTRACHEAL INTUBATION or TRACHEOSTOMY – may be necessary if severe airway obstruction develops (see APPENDIX 1: BASIC FIRST AID). A?ected patients should rest their voice and avoid smoking.
Chronic laryngitis can result from repeated attacks of acute laryngitis; excessive use of the voice – loud and prolonged, singing or shouting; tumours, which may be benign or malignant; or secondary to diseases such as TUBERCULOSIS and SYPHILIS.
Benign tumours or small nodules, such as singer’s nodules, may be surgically removed by direct laryngoscopy under general anaesthetic; while cancer of the larynx may be treated either by RADIOTHERAPY or by SURGERY, depending on the extent of the disease. Hoarseness may be the only symptom of vocal-chord disturbance or of laryngeal cancer: any case which has lasted for six weeks should be referred for a specialist opinion.
Laryngectomy clubs are being established
A laryngoscopic view of the interior of the larynx.
throughout the country to support patients following laryngectomy. Speech therapists provide speech rehabilitation.... larynx, disorders of
The cortex contains specialized capillaries called glomeruli, which, together with a series of tubules, make up the nephrons, the filtering units of the kidney. The nephrons filter blood under pressure and then selectively reabsorb water and certain other substances back into the blood. Urine is formed from substances that are not reabsorbed. The urine is conducted through tubules to the renal pelvis (the central collecting area of the kidney) and then through tubes called ureters to the bladder.
The kidneys also regulate the body’s fluid balance.
To do this, the kidneys excrete excess water, and when water is lost from the body (for example as a result of sweating), they conserve it (see ADH).
In addition, the kidneys control the body’s acid–base balance by adjusting urine acidity.
The kidneys are also involved in hormonal regulation of red blood cell production and blood pressure.... kidney
Dominant genes A dominant characteristic is an e?ect which is produced whenever a gene or gene defect is present. If a disease is due to a dominant gene, those affected are heterozygous – that is, they only carry a fault in the gene on one of the pair of chromosomes concerned. A?ected people married to normal individuals transmit the gene directly to one-half of the children, although this is a random event just like tossing a coin. HUNTINGTON’S CHOREA is due to the inheritance of a dominant gene, as is neuro?bromatosis (see VON RECKLINGHAUSEN’S DISEASE) and familial adenomatous POLYPOSIS of the COLON. ACHONDROPLASIA is an example of a disorder in which there is a high frequency of a new dominant mutation, for the majority of affected people have normal parents and siblings. However, the chances of the children of a parent with the condition being affected are one in two, as with any other dominant characteristic. Other diseases inherited as dominant characteristics include spherocytosis, haemorrhagic telangiectasia and adult polycystic kidney disease.
Recessive genes If a disease is due to a recessive gene, those affected must have the faulty gene on both copies of the chromosome pair (i.e. be homozygous). The possession of a single recessive gene does not result in overt disease, and the bearer usually carries this potentially unfavourable gene without knowing it. If that person marries another carrier of the same recessive gene, there is a one-in-four chance that their children will receive the gene in a double dose, and so have the disease. If an individual sufferer from a recessive disease marries an apparently normal person who is a heterozygous carrier of the same gene, one-half of the children will be affected and the other half will be carriers of the disease. The commonest of such recessive conditions in Britain is CYSTIC FIBROSIS, which affects about one child in 2,000. Approximately 5 per cent of the population carry a faulty copy of the gene. Most of the inborn errors of metabolism, such as PHENYLKETONURIA, GALACTOSAEMIA and congenital adrenal hyperplasia (see ADRENOGENITAL SYNDROME), are due to recessive genes.
There are characteristics which may be incompletely recessive – that is, neither completely dominant nor completely recessive – and the heterozygotus person, who bears the gene in a single dose, may have a slight defect whilst the homozygotus, with a double dose of the gene, has a severe illness. The sickle-cell trait is a result of the sickle-cell gene in single dose, and sickle-cell ANAEMIA is the consequence of a double dose.
Sex-linked genes If a condition is sex-linked, affected males are homozygous for the mutated gene as they carry it on their single X chromosome. The X chromosome carries many genes, while the Y chromosome bears few genes, if any, other than those determining masculinity. The genes on the X chromosome of the male are thus not matched by corresponding genes on the Y chromosome, so that there is no chance of the Y chromosome neutralising any recessive trait on the X chromosome. A recessive gene can therefore produce disease, since it will not be suppressed by the normal gene of the homologous chromosome. The same recessive gene on the X chromosome of the female will be suppressed by the normal gene on the other X chromosome. Such sex-linked conditions include HAEMOPHILIA, CHRISTMAS DISEASE, DUCHENNE MUSCULAR
DYSTROPHY (see also MUSCLES, DISORDERS OF – Myopathy) and nephrogenic DIABETES INSIPIDUS.
If the mother of an affected child has another male relative affected, she is a heterozygote carrier; half her sons will have the disease and half her daughters will be carriers. The sister of a haemophiliac thus has a 50 per cent chance of being a carrier. An affected male cannot transmit the gene to his son because the X chromosome of the son must come from the mother; all his daughters, however, will be carriers as the X chromosome for the father must be transmitted to all his daughters. Hence sex-linked recessive characteristics cannot be passed from father to son. Sporadic cases may be the result of a new mutation, in which case the mother is not the carrier and is not likely to have further affected children. It is probable that one-third of haemophiliacs arise as a result of fresh mutations, and these patients will be the ?rst in the families to be affected. Sometimes the carrier of a sex-linked recessive gene can be identi?ed. The sex-linked variety of retinitis pigmentosa (see EYE, DISORDERS OF) can often be detected by ophthalmoscopic examination.
A few rare disorders are due to dominant genes carried on the X chromosome. An example of such a condition is familial hypophosphataemia with vitamin-D-resistant RICKETS.
Polygenic inheritance In many inherited conditions, the disease is due to the combined action of several genes; the genetic element is then called multi-factorial or polygenic. In this situation there would be an increased incidence of the disease in the families concerned, but it will not follow the Mendelian (see MENDELISM; GENETIC CODE) ratio. The greater the number of independent genes involved in determining a certain disease, the more complicated will be the pattern of inheritance. Furthermore, many inherited disorders are the result of a combination of genetic and environmental in?uences. DIABETES MELLITUS is the most familiar of such multi-factorial inheritance. The predisposition to develop diabetes is an inherited characteristic, although the gene is not always able to express itself: this is called incomplete penetrance. Whether or not the individual with a genetic predisposition towards the disease actually develops diabetes will also depend on environmental factors. Diabetes is more common in the relatives of diabetic patients, and even more so amongst identical twins. Non-genetic factors which are important in precipitating overt disease are obesity, excessive intake of carbohydrate foods, and pregnancy.
SCHIZOPHRENIA is another example of the combined effects of genetic and environmental in?uences in precipitating disease. The risk of schizophrenia in a child, one of whose parents has the disease, is one in ten, but this ?gure is modi?ed by the early environment of the child.... genetic disorders
There are also more than 200 identi?ed disorders described as inborn errors of metabolism. Some cause few problems; others are serious threats to an individual’s life. Individual disorders are, fortunately, rare – probably one child in 10,000 or 100,000; overall these inborn errors affect around one child in 1,000. Examples include GALACTOSAEMIA, PHENYLKETONURIA, porphyrias, TAY SACHS DISEASE and varieties of mucopolysaccharidosis, HOMOCYSTINURIA and hereditary fructose (a type of sugar) intolerance.... metabolic disorders
Dumbness is the inability to pronounce the sounds that make up words. DEAFNESS is the most important cause, being due to a congenital brain defect, or acquired brain disease, such as tertiary SYPHILIS. When hearing is normal or only mildly impaired, dumbness may be due to a structural defect such as tongue-tie or enlarged tonsils and adenoids, or to ine?cient voice control, resulting in lisping or lalling. Increased tension is a common cause of STAMMERING; speech disorders may occasionally be of psychological origin.
Normal speech may be lost in adulthood as a result of a STROKE or head injury. Excessive use of the voice may be an occupational hazard; and throat cancer may require a LARYNGECTOMY, with subsequent help in communication. Severe psychiatric disturbance may be accompanied by impaired social and communication skills. (See also VOICE AND SPEECH.)
Treatment The underlying cause of the problem should be diagnosed as early as possible; psychological and other specialist investigations should be carried out as required, and any physical defect should be repaired. People who are deaf and unable to speak should start training in lip-reading as soon as possible, and special educational methods aimed at acquiring a modulated voice should similarly be started in early childhood – provided by the local authority, and continued as required. Various types of speech therapy or PSYCHOTHERAPY may be appropriate, alone or in conjunction with other treatments, and often the ?nal result may be highly satisfying, with a good command of language and speech being obtained.
Help and advice may be obtained from AFASIC (Unlocking Speech and Language).... speech disorders
Gender is determined by a combination of genetic and environmental factors, in which the in?uence of family upbringing is an important factor. When physical sexual characteristics are ambiguous, the child’s gender identity can usually be established if the child is reared as being clearly male or female. Should, however, the child be confused about its sexual identity, the uncertainty may continue into adult life. Transsexuals generally experience con?icts of identity in childhood, and such problems usually occur by the age of two years. In this type of identity disorder, which occurs in one in 30,000 male births and one in 100,000 female births, the person believes that he or she is the victim of a biological accident, trapped in a body different from what is felt to be his or her true sex.
Treatment is di?cult: psychotherapy and hormone treatment may help, but some affected individuals want surgery to change their body’s sexual organs to match their innately felt sexual gender. The decision to seek a physical sex change raises major social problems for individuals, and ethical problems for their doctors. Surgery, which is not always successful in the long term, requires careful assessment, discussion and planning. It is important to preclude mental illness; results in homosexual men who have undergone surgery are not usually satisfactory. Advice and information may be obtained from Gender Identity Consultancy Services.... gender identity disorders
Cramp Painful spasm of a muscle usually caused by excessive and prolonged contraction of the muscle ?bres. Cramps are common, especially among sportsmen and women, normally lasting a short time. The condition usually occurs during or immediately following exercise as a result of a build-up of LACTIC ACID and other chemical by-products in the muscles
– caused by the muscular e?orts. Cramps may occur more frequently, especially at night, in people with poor circulation, when the blood is unable to remove the lactic acid from the muscles quickly enough.
Repetitive movements such as writing (writer’s cramp) or operating a keyboard can cause cramp. Resting muscles may suffer cramp if a person sits or lies in an awkward position which limits local blood supply to them. Profuse sweating as a result of fever or hot weather can also cause cramp in resting muscle, because the victim has lost sodium salts in the sweat; this disturbs the biochemical balance in muscle tissue.
Treatment is to massage and stretch the affected muscle – for example, cramp in the calf muscle may be relieved by pulling the toes on the affected leg towards the knee. Persistent night cramps sometimes respond to treatment with a drug containing CALCIUM or QUININE. If cramp persists for an hour or more, the person should seek medical advice, as there may be a serious cause such as a blood clot impeding the blood supply to the area affected.
Dystrophy See myopathy below.
In?ammation (myositis) of various types may occur. As the result of injury, an ABSCESS may develop, although wounds affecting muscle generally heal well. A growth due to SYPHILIS, known as a gumma, sometimes forms a hard, almost painless swelling in a muscle. Rheumatism is a vague term traditionally used to de?ne intermittent and often migratory discomfort, sti?ness or pain in muscles and joints with no obvious cause. The most common form of myositis is the result of immunological damage as a result of autoimmune disease. Because it affects many muscles it is called POLYMYOSITIS.
Myasthenia (see MYASTHENIA GRAVIS) is muscle weakness due to a defect of neuromuscular conduction.
Myopathy is a term applied to an acquired or developmental defect in certain muscles. It is not a neurological disease, and should be distinguished from neuropathic conditions (see NEUROPATHY) such as MOTOR NEURONE DISEASE (MND), which tend to affect the distal limb muscles. The main subdivisions are genetically determined, congenital, metabolic, drug-induced, and myopathy (often in?ammatory) secondary to a distant carcinoma. Progressive muscular dystrophy is characterised by symmetrical wasting and weakness, the muscle ?bres being largely replaced by fatty and ?brous tissue, with no sensory loss. Inheritance may take several forms, thus affecting the sex and age of victims.
The commonest type is DUCHENNE MUSCULAR DYSTROPHY, which is inherited as a sex-linked disorder. It nearly always occurs in boys.
Symptoms There are three chief types of myopathy. The commonest, known as pseudohypertrophic muscular dystrophy, affects particularly the upper part of the lower limbs of children. The muscles of the buttocks, thighs and calves seem excessively well developed, but nevertheless the child is clumsy, weak on his legs, and has di?culty in picking himself up when he falls. In another form of the disease, which begins a little later, as a rule at about the age of 14, the muscles of the upper arm are ?rst affected, and those of the spine and lower limbs become weak later on. In a third type, which begins at about this age, the muscles of the face, along with certain of the shoulder and upper arm muscles, show the ?rst signs of wasting. All the forms have this in common: that the affected muscles grow weaker until their power to contract is quite lost. In the ?rst form, the patients seldom reach the age of 20, falling victims to some disease which, to ordinary people, would not be serious. In the other forms the wasting, after progressing to a certain extent, often remains stationary for the rest of life. Myopathy may also be acquired when it is the result of disease such as thyrotoxicosis (see under THYROID GLAND, DISEASES OF), osteomalacia (see under BONE, DISORDERS OF) and CUSHING’S DISEASE, and the myopathy resolves when the primary disease is treated.
Treatment Some myopathies may be the result of in?ammation or arise from an endocrine or metabolic abnormality. Treatment of these is the treatment of the cause, with supportive physiotherapy and any necessary physical aids while the patient is recovering. Treatment for the hereditary myopathies is supportive since, at present, there is no cure – although developments in gene research raise the possibility of future treatment. Physiotherapy, physical aids, counselling and support groups may all be helpful in caring for these patients.
The education and management of these children raise many diffculties. Much help in dealing with these problems can be obtained from Muscular Dystrophy Campaign.
Myositis ossi?cans, or deposition of bone in muscles, may be congenital or acquired. The congenital form, which is rare, ?rst manifests itself as painful swellings in the muscles. These gradually harden and extend until the child is encased in a rigid sheet. There is no e?ective treatment and the outcome is fatal.
The acquired form is a result of a direct blow on muscle, most commonly on the front of the thigh. The condition should be suspected whenever there is severe pain and swelling following a direct blow over muscle. The diagnosis is con?rmed by hardening of the swelling. Treatment consists of short-wave DIATHERMY with gentle active movements. Recovery is usually complete.
Pain, quite apart from any in?ammation or injury, may be experienced on exertion. This type of pain, known as MYALGIA, tends to occur in un?t individuals and is relieved by rest and physiotherapy.
Parasites sometimes lodge in the muscles, the most common being Trichinella spiralis, producing the disease known as TRICHINOSIS (trichiniasis).
Rupture of a muscle may occur, without any external wound, as the result of a spasmodic e?ort. It may tear the muscle right across – as sometimes happens to the feeble plantaris muscle in running and leaping – or part of the muscle may be driven through its ?brous envelope, forming a HERNIA of the muscle. The severe pain experienced in many cases of LUMBAGO is due to tearing of one of the muscles in the back. These conditions are usually relieved by rest and massage. Partial muscle tears, such as occur in sport, require more energetic treatment: in the early stages this consists of the application of an ice or cold-water pack, ?rm compression, elevation of the affected limb, rest for a day or so and then gradual mobilisation (see SPORTS MEDICINE).
Tumours occur occasionally, the most common being ?broid, fatty, and sarcomatous growths.
Wasting of muscles sometimes occurs as a symptom of disease in other organs: for example, damage to the nervous system, as in poliomyelitis or in the disease known as progressive muscular atrophy. (See PARALYSIS.)... muscles, disorders of
They include branchial cyst and branchial fistula.
A branchial cyst is a soft swelling, containing a pus-like or clear fluid, that appears on the side of the neck in early adulthood.
Treatment is by surgical removal.
A branchial fistula occurs between the back of the throat and the external surface of the neck, where it appears as a small hole, usually noted at birth.
A hole in the neck that does not extend to the back of the throat is a branchial cleft sinus.
A branchial fistula or cleft sinus may discharge mucus or pus and may be removed surgically.... branchial disorders
The most common cervical infections are sexually transmitted, such as gonorrhoea, chlamydial infections, and trichomoniasis.
Viral infections of the cervix include those due to the human papilloma virus and the herpes simplex virus (see warts, genital; herpes, genital).
Polyps are noncancerous growths on the cervix.
Cancerous growths (see cervix, cancer of) are preceded by changes in the surface cells (cervical dysplasias), which can be detected by a cervical smear test.... cervix, disorders of
Infection is the most common cause of ear disorders; it may occur in the ear canal, leading to otitis externa, or affect the middle ear, causing otitis media. This can lead to perforation of the eardrum (see eardrum, perforated). Persistent glue ear, often due to infection, is the most common cause of childhood hearing difficulties. Viral infection of the inner ear may cause labyrinthitis.
Cauliflower ear is the result of one large or several small injuries to the pinna. Perforation of the eardrum can result from poking objects into the ear or loud noise. Prolonged exposure to loud noise can cause tinnitus and/or deafness. Pressure changes associated with flying or scuba diving can also cause minor damage (see barotrauma).Tumours of the ear are rare. Acoustic neuroma is a noncancerous tumour of the acoustic nerve that may press on structures in the ear to cause deafness, tinnitus, and problems with balance.
In cholesteatoma, skin cells and debris collect in the middle ear. Obstruction of the ear canal is most often the result of earwax, although in small children, an object may have been pushed into the ear (see ear, foreign body in).
In otosclerosis, a hereditary condition, a bone in the middle ear becomes fixed, causing deafness. Meniérè’s disease is an uncommon condition in which deafness, vertigo, and tinnitus result from the accumulation of fluid in the inner ear. Deafness in many elderly people is due to presbyacusis, in which hair cells in the cochlea deteriorate.
Certain drugs, such as aminoglycoside drugs and some diuretic drugs, can damage ear function.... ear, disorders of
In premature ejaculation, emission of semen occurs before or almost immediately following penetration. Premature ejaculation is the most common sexual problem in men, and is often due to over-stimulation or anxiety about sexual performance. If the problem occurs frequently, sexual counselling and techniques for delaying ejaculation may help (see sex therapy).
Inhibited ejaculation is a rare condition in which erection is normal, or even prolonged, but ejaculation is abnormally delayed or fails to occur. The problem may be psychological in origin, in which case counselling may help, or it may be a complication of a disorder such as diabetes mellitus or alcohol dependence. In some cases, inhibited ejaculation occurs as a side effect of particular drugs, such as some antihypertensive and antidepressant drugs.
In retrograde ejaculation, the valve at the base of the bladder, which normally closes during ejaculation, stays open. As a result, ejaculate is forced back into the bladder. Retrograde ejaculation may occur as a result of a neurological disease, after surgery on the bladder or prostatectomy. There is no treatment, but intercourse with a full bladder can sometimes result in normal ejaculation. (See also azoospermia; psychosexual dysfunction; sexual problems.)... ejaculation, disorders of
Growth in an abnormal direction may be due to injury to the lid or, more commonly, to infection.
Severe blepharitis may destroy the roots of the lashes.
Trachoma, an infection in which the lid is distorted by scarring, may lead to trichiasis.
With age, the lashes become finer and fewer.... eyelashes, disorders of
There is no apparent cause for a factitious disorder other than a wish for attention.
The most common disorder of this type, Munchausen’s syndrome, is characterized by physical symptoms.
In a second form, Ganser’s syndrome, there are psychological symptoms.
These disorders differ from malingering, in which the person claims to be ill for a particular purpose, such as obtaining time off work.... factitious disorders
Anorexia nervosa Often called the slimmer’s disease, this is a syndrome characterised by the loss of at least a quarter of a person’s normal body weight; by fear of normal weight; and, in women, by AMENORRHOEA. An individual’s body image may be distorted so that the sufferer cannot judge real weight and wants to diet even when already very thin.
Anorexia nervosa usually begins in adolescence, affecting about 1–2 per cent of teenagers and college students at any time. It is 20 times more common among women than men. Up to 10 per cent of sufferers’ sisters also have the syndrome. Anorexia may be linked with episodes of bulimia (see below).
The symptoms result from secretive self-starvation, usually with excessive exercise, self-induced vomiting, and misuse of laxatives. An anorexic (or anorectic) person may wear layers of baggy clothes to keep warm and to hide the ?gure. Starvation can cause serious problems such as ANAEMIA, low blood pressure, slow heart rate, swollen ankles, and osteoporosis. Sudden death from heart ARRHYTHMIA may occur, particularly if the sufferer misuses DIURETICS to lose weight and also depletes the body’s level of potassium.
There is probably no single cause of anorexia nervosa. Social pressure to be thin seems to be an important factor and has increased over the past 20–30 years, along with the incidence of the syndrome. Psychological theories include fear of adulthood and fear of losing parents’ attention.
Treatment should start with the general practitioner who should ?rst rule out other illnesses causing similar signs and symptoms. These include DEPRESSION and disorders of the bowel, PITUITARY GLAND, THYROID GLAND, and OVARIES.
If the diagnosis is clearly anorexia nervosa, the general practitioner may refer the sufferer to a psychiatrist or psychologist. Moderately ill sufferers can be treated by COGNITIVE BEHAVIOUR THERAPY. A simple form of this is to agree targets for daily calorie intake and for acceptable body weight. The sufferer and the therapist (the general practitioner or a member of the psychiatric team) then monitor progress towards both targets by keeping a diary of food intake and measuring weight regularly. Counselling or more intensely personal PSYCHOTHERAPY may help too. Severe life-threatening complications will need urgent medical treatment in hospital, including rehydration and feeding using a nasogastric tube or an intravenous drip.
About half of anorectic sufferers recover fully within four years, a quarter improve, and a quarter remain severely underweight with (in the case of women) menstrual abnormalities. Recovery after ten years is rare and about 3 per cent die within that period, half of them by suicide.
Bulimia nervosa is a syndrome characterised by binge eating, self-induced vomiting and laxative misuse, and fear of fatness. There is some overlap between anorexia nervosa and bulimia but, unlike the former, bulimia may start at any age from adolescence to 40 and is probably more directly linked with ordinary dieting. Bulimic sufferers say that, although they feel depressed and guilty after binges, the ‘buzz’ and relief after vomiting and purging are addictive. They often respond well to cognitive behaviour therapy.
Bulimia nervosa does not necessarily cause weight loss because the binges – for example of a loaf of bread, a packet of cereal, and several cans of cold baked beans at one sitting – are cancelled out by purging, by self-induced vomiting and by brief episodes of starvation. The full syndrome has been found in about 1 per cent of women but mild forms may be much more common. In one survey of female college students, 13 per cent admitted to having had bulimic symptoms.
Bulimia nervosa rarely leads to serious physical illness or death. However, repeated vomiting can cause oesophageal burns, salivary gland infections, small tears in the stomach, and occasionally dehydration and chemical imbalances in the blood. Inducing vomiting using ?ngers may produce two tell-tale signs – bite marks on the knuckles and rotten, pitted teeth.
Those suffering from this condition may obtain advice from the Eating Disorders Association.... eating disorders
In general, genetic factors do not play a large part in causing heart disorders, however they do contribute to the hyperlipidaemias that predispose a person to atherosclerosis and coronary artery disease. Structural abnormalities in the heart are among the most common birth defects (see heart disease, congenital).
Infections after birth may result in endocarditis or myocarditis. Tumours arising from the heart tissues are rare. They include noncancerous myxomas and cancerous sarcomas.
The heart muscle may become thin and flabby from lack of protein and calories. Thiamine (vitamin B1) deficiency, common in alcoholics, causes beriberi with congestive heart failure. Alcohol poisoning over many years may cause a type of cardiomyopathy. Obesity is an important factor in heart disease, probably through its effect on other risk factors, such as hypertension, diabetes, and cholesterol.
The coronary arteries may become narrowed due to atherosclerosis, depriving areas of heart muscle of oxygen. The result may be angina pectoris or, eventually, a myocardial infarction.
Some drugs, such as the anticancer drug doxorubicin, tricyclic antidepressants, and even drugs used to treat heart disease, may disturb the heartbeat or damage the heart muscle.
Many common and serious heart disorders may be a complication of an underlying condition, such as cardiomyopathy or a congenital defect. Such disorders include cardiac arrhythmia, some cases of heart block, and heart failure. Cor pulmonale is a failure of the right side of the heart as a consequence of lung disease.... heart, disorders of
The mechanisms by which the body loses unwanted heat are controlled by the hypothalamus in the brain. When blood temperature rises, the hypothalamus sends out nerve impulses to stimulate the sweat glands and dilate blood vessels in the skin, which cools the body down. However, excessive sweating may result in an imbalance of salts and fluids in the body, which may lead to heat cramps or heat exhaustion. When the hypothalamus is disrupted (for example, by a fever), the body may overheat, leading to heatstroke. Excessive external heat may cause prickly heat.
Most heat disorders can be prevented by gradual acclimatization to hot conditions and taking salt tablets or solution.
A light diet and frequent cool baths or showers may also help.
Alcohol and strenuous exercise should be avoided.... heat disorders
Congenital or inherited deficiencies can occur in either of the 2 prongs of the adaptive immune system: humoral or cellular. Deficiencies of the humoral system include hypogammaglobulinaemia and agammaglobulinaemia. The former may cause few or no symptoms, depending on the severity of the deficiency, but agammaglobulinaemia can be fatal if not treated with immunoglobulin. Congenital deficiencies of T-lymphocytes may lead to problems such as persistent and widespread candidiasis (thrush). A combined deficiency of both humoral and cellular components of the immune system, called severe combined immunodeficiency (SCID), is usually fatal in the 1st year of life unless treatment can be given by bone marrow transplant.
Acquired immunodeficiency may be due either to disease processes (such as infection with HIV, which leads to AIDS) or damage to the immune system as a result of its suppression by drugs. Severe malnutrition and many cancers can also cause immunodeficiency. Mild immunodeficiency arises through a natural decline in immune defences with age.... immunodeficiency disorders
Structural abnormalities may be present from birth (congenital) or may develop later. They cause blockage of the intestine (see intestine, blockage of) and include atresia, stenosis, and volvulus. In newborns, meconium (fetal intestinal contents) may block the intestine.
Generalized inflammation of the intestine may result from viral or bacterial infections or from noninfectious causes, as in ulcerative colitis and Crohn’s disease. Gastroenteritis is the term commonly applied to inflammation of the stomach and intestines. Infection encompasses food poisoning, traveller’s diarrhoea, typhoid fever, cholera, amoebiasis, and giardiasis. Intestinal worm infestations include roundworms and tapeworms. Sometimes inflammation is localized, such as in appendicitis and diverticular disease.
Tumours of the small intestine are rare, but noncancerous growths, lymphomas, and carcinoid tumours (causing carcinoid syndrome) occur. Tumours of the large intestine are common (see colon, cancer of; rectum, cancer of). Some forms of familial polyposis may progress to cancer. Impaired blood supply (ischaemia) to the intestine may occur as a result of partial or complete obstruction of the arteries in the abdominal wall (from diseases such as atherosclerosis) or from the blood vessels being compressed or trapped, as in intussusception or hernias. Loss of blood supply may cause gangrene.
Other disorders that affect the intestine include peptic ulcers, diverticulosis, malabsorption, coeliac disease, and irritable bowel syndrome.... intestine, disorders of
Kidney biopsy is performed to investigate and diagnose serious kidney disorders, such as glomerulonephritis, proteinuria, nephrotic syndrome, and acute kidney failure, or to assess the kidneys’ response to treatment.
There are 2 basic techniques: percutaneous needle biopsy, in which a hollow needle is passed through the skin into the kidney under local anaesthesia; and open surgery under general anaesthesia.... kidney biopsy
Polycystic kidney disease is distinguished from multiple simple kidney cysts, which occur commonly with age.
There are 2 types of polycystic disease.
The most common usually becomes apparent in middle age, producing abdominal swelling, pain, and blood in the urine.
As the disease progresses, hypertension and kidney failure may result.
The rare type causes enlargement of the kidneys and kidney failure in infants and young children.
There is no effective treatment for preserving kidney function in either type, but symptoms of kidney failure can be treated by dialysis and kidney transplant.... kidney, polycystic
The best known of these neurocutaneous disorders is neurofibromatosis, in which there are brown patches on the skin and numerous fibrous nodules on the skin and nerves. Another example is tuberous sclerosis, which is characterized by small skin-coloured swellings over the cheeks and nose, mental deficiency, and epilepsy.... neurocutaneous disorders
cystic fibrosis. The lungs can also be affected by allergic disorders. The most important of these is asthma. Another such disorder is allergic alveolitis, which is usually a reaction to dust of plant or animal origin. Irritation of the airways, usually by tobacco-smoking, can cause diseases characterized by damage to lung tissue and narrowing of the airways (see pulmonary disease, chronic obstructive). The lungs can also be affected by cancerous tumours; lung cancer is one of the most common cancers. Noncancerous lung tumours are uncommon.
Injury to a lung, usually resulting from penetration of the chest wall, can cause the lung to collapse (see pneumothorax; haemothorax). Damage to the interior of the lungs can be caused by inhalation of toxic substances (see asbestosis; silicosis). Blood supply to the lungs may be reduced by pulmonary embolism.
Lung disorders can be investigated in various ways, such as chest X-ray, bronchoscopy, and pulmonary function tests.... lung, disorders of
Dysmenorrhoea (painful periods) is the most common type of menstrual disorder. Other types of menstrual disorder are amenorrhoea (absence of menstruation), polymenorrhoea (too frequent menstruation), oligomenorrhoea (infrequent periods or scanty blood loss), and menorrhagia (excessive bleeding).
Some women have extreme variations in the length of menstrual cycles or menstrual periods, or in the amount of blood lost (see menstruation, irregular).... menstruation, disorders of
A diet deficient in carbohydrates is almost inevitably also deficient in protein, leading to the development of protein–calorie malnutrition. Such malnutrition is most often seen as a result of severe poverty and famine (see kwashiorkor; marasmus).
Deficiency of specific nutrients is commonly associated with a disorder of the digestive system, such as coeliac disease, Crohn’s disease, or pernicious anaemia (see anaemia, megaloblastic).
Inadequate intake of protein and calories may also occur in people who excessively restrict their diet to lose weight (see anorexia nervosa), hold mistaken beliefs about diet and health (see food fad), or suffer from a loss of interest in food associated with alcohol dependence or drug dependence.Obesity results from taking in more energy from the diet than is used up by the body. Nutritional disorders may also result from an excessive intake of minerals and vitamins. An excessive intake of saturated fat is thought to be a contributory factor in coronary artery disease and in some forms of cancer.
Naturally occurring toxins can interfere with the digestion, absorption, and/or utilization of nutrients, or can cause specific disorders due to their toxic effects: for example, the ergot fungus found on rye can cause ergotism.... nutritional disorders
Infections of the oesophagus are rare but may occur in immunosuppressed patients. The most common are herpes simplex and candidiasis (thrush). Oesophagitis is usually due to reflux of stomach contents, causing heartburn. Corrosive oesophagitis can occur as a result of swallowing caustic chemicals. Both may cause an oesophageal stricture.
Congenital defects include oesophageal atresia, which requires surgery soon after birth. Tumours of the oesophagus are quite common; about 90 per cent are cancerous (see oesophagus, cancer of). Injury to the oesophagus is most commonly caused by a tear or rupture due to severe vomiting and retching. (See also swallowing difficulty.)... oesophagus, disorders of
Specific types of personality disorders are divided into 3 groups but there is often overlap. The 1st group is characterized by eccentric behaviour. Paranoid people show suspiciousness and mistrust of others, schizoid people are cold emotionally, and schizotypal personalities have behaviour oddities similar to those of schizophrenia, but less severe.In the 2nd group, behaviour tends to be dramatic. Histrionic people are excitable and constantly crave stimulation, narcissists have an exaggerated sense of their own importance (see narcissism), and people with antisocial personality disorder fail to conform to accepted social standards of behaviour.
People in the 3rd group show anxiety and fear. Dependent personalities lack the self-confidence to function independently (see dependence). Those with compulsive personalities are rigid in their habits (see obsessive–compulsive disorder), and passive-aggressive people resist demands from others.
Treatment is usually counselling, psychotherapy, and behaviour therapy.... personality disorders
Acne is common in adolescents and is partly related to the action of androgen hormones.
Inflammation of the skin occurs in dermatitis, eczema, and skin allergy.
The skin is also vulnerable to injuries such as burns, cuts, and bites (see bites, animal; insect bites).... skin, disorders of the
Acute in?ammation is generally the result of a viral infection (see COLD, COMMON) affecting the mucous membrane and paranasal sinuses (see SINUSITIS); less commonly it results from the inhalation of irritant gases. Boils may develop just inside the entrance to the nose, causing pain; these are potentially troublesome as infection can spread to the sinuses. HAY FEVER is one distressing form of acute rhinitis.
Malformations are of various kinds. Racial and familial variations in the external nose occur and may be a reason for RHINOPLASTY. Di?erences in the size and shape of the nose occur, often forming the starting point for chronic in?ammation of the nose, perennial rhinitis (all the year round), hay fever, or ASTHMA. More commonly, obstruction results from nasal polyps or adenoids, leading to inhalation through the mouth. Adenoids are an overgrowth of glandular tissue at the back of the throat, into which the nose opens. Polyps are growths of soft jelly-like character: they arise from chronic in?ammation associated with allergic rhinitis, chronic sinusitis, asthma, and aspirin abuse. Large polyps can cause erosion of the nasal bones and should be surgically removed.
Bleeding (see HAEMORRHAGE).
Foreign bodies At ?rst these may not cause any symptoms, but in time they can cause obstruction of the affected nostril with a foul-smelling bloody discharge. The problem is common with small children who tend to push small objects into their noses. Foreign bodies require removal, sometimes in hospital. Anyone attempting to remove a foreign body should take care not to push it further into the nose.
Loss of sense of smell, or anosmia, may be temporary or permanent. Temporary anosmia is caused by conditions of the nose which are reversible, whereas permanent
anosmia is caused by conditions which destroy the OLFACTORY NERVES. Temporary conditions are those such as the common cold, or other in?ammatory conditions of the nasal mucosa or the presence of nasal polyps (see above). Permanent anosmia may follow in?uenzal NEURITIS or it may also follow injuries to the brain and fractures of the skull involving the olfactory nerves.
Injury to nose The commonest injury is a fracture of the nasal bones or displacement of the cartilage that forms the bridge of the nose. The nasal SEPTUM may also be displaced sideways by a lateral blow. Sporting activities, especially boxing and rugby football, are commonly a cause of nasal injury. If a fracture is suspected, or if there is substantial tissue swelling, an X-ray examination is necessary. Resetting a damaged bone should be done either immediately, before swelling makes surgery di?cult, or ten days or so later when the swelling has subsided. Results are usually good, ensuring a clear airway as well as a restored pro?le. It is not unusual for the cheek-bone to sustain a depressed fracture at the same time as the nose is broken. Careful assessment and prompt surgery are called for. (For more information on fractures, see under BONE, DISORDERS OF).
Rhinitis In?ammation of the MUCOUS MEMBRANE lining the nose. Symptoms include nasal discharge and obstruction, sneezing and sometimes pain in the sinuses. There are several types of rhinitis:
•Allergic – due to allergy to dust, pollen or other airborne particles. Also called hay fever, allergic rhinitis causes a runny nose, sneezing and local congestion. It affects up to 10 per cent of the population and is more common in people suffering from other allergic disorders such as asthma or eczema (see DERMATITIS). Skin tests help to identify the causative ALLERGEN which the sufferer can then try to avoid, although in the case of pollen this is di?cult. Decongestant drugs, ANTIHISTAMINE DRUGS, and CORTICOSTEROIDS may help, as can SODIUM CROMOGLYCATE inhaled regularly during the pollen season. A desensitisation course to a particular allergen sometimes provides long-term relief.
Atrophic rhinitis is caused by a deterioration in the nasal mucous membrane as a result of chronic bacterial infection, nasal surgery or AGEING. Symptoms include persistent nasal infection and discharge and loss of sense of smell. ANTIBIOTICS and, in some cases, OESTROGENS alleviate the symptoms.
Hypertrophic rhinitis results from repeated nasal infection, and is characterised by thickened nasal membranes and congestion of the nasal veins. Removal of thickened mucosa may help severe cases.
Vasomotor rhinitis occurs when the mucosa becomes oversensitive to stimuli such as pollutants, temperature changes or certain foods or medicines. It may occur as a result of emotional disturbances and is common in pregnancy.
Viral rhinitis occurs as a result of infection by the common cold virus; treatment is symptomatic. Sinusitis is sometimes a complication.... nose, disorders of
Pancreatic cancer The incidence of pancreatic cancer is rising: around 7,000 cases are now diagnosed annually in the UK, accounting for 1–2 per cent of all malignancies. There is an established association with heavy cigarette-smoking, and the cancer is twice as common in patients with diabetes mellitus as compared with the general population. Cancer of the pancreas is hard to diagnose; by the time symptoms occur the tumour may be di?cult to treat surgically – with PALLIATIVE bypass surgery the only procedure.
Chronic pancreatitis may be painless; it leads to pancreatic failure causing MALABSORPTION SYNDROME and diabetes mellitus, and the pancreas becomes calci?ed with shadowing on X-RAYS. The malabsorption is treated by a low-fat diet with pancreatic enzyme supplements; the diabetes with insulin; and pain is treated appropriately. Surgery may be required.
Acute pancreatitis An uncommon disease of the pancreas which may start gradually or suddenly, usually accompanied by severe abdominal pain which often radiates through to the back. Biliary tract disease and alcohol account for 80 per cent of patients admitted with acute pancreatitis, while other causes include drugs (see AZATHIOPRINE and DIURETICS) and infections such as MUMPS. Patients are acutely ill with TACHYCARDIA, fever and low blood pressure; many go into SHOCK. The condition may be mistaken for a perforated PEPTIC ULCER, except that in acute pancreatitis the blood concentration of AMYLASE is raised. The main complication is the formation of a PSEUDOCYST. Treatment includes intravenous feeding, ANTICHOLINERGIC drugs and ANALGESICS. Regular measurements of blood GLUCOSE, CALCIUM, amylase and blood gases are required. Abdominal ULTRASOUND may identify gall-stones (see under GALL-BLADDER, DISEASES OF). If the patient deteriorates, he or she should be admitted for intensive care as haemorrhagic pancreatic necrosis may be developing. LAPAROTOMY and DEBRIDEMENT may be called for. Mortality is 5–10%.... pancreas, disorders of
DIABETES INSIPIDUS, a condition characterised by the passing of a large volume of URINE every day, is due to lack of the antidiuretic hormone (see VASOPRESSIN). Enhanced production of the ADRENOCORTICOTROPHIC HORMONE (ACTH) leads to CUSHING’S SYNDROME. Excessive production of PROLACTIN by micro or macro adenomas (benign tumours) leads to hyperprolactinaemia and consequent AMENORRHOEA and GALACTORRHOEA. Some adenomas do not produce any hormone but cause effects by damaging the pituitary cells and inhibiting their hormone production.
The most sensitive cells to extrinsic pressure are the gonadotrophin-producing cells and the growth-hormone producing cells, so that if the tumour occurs in childhood, growth hormone will be suppressed and growth will slow. Gonadotrophin hormone suppression will prevent the development of puberty and, if the tumour occurs after puberty, will result in amenorrhoea in the female and lack of LIBIDO in both sexes. The thyroid-stimulating hormone cells are the next to suffer and the pressure effects on these cells will result in hypothyroidism (see under THYROID GLAND, DISEASES OF).
Fortunately the ACTH-producing cells are the most resistant to extrinsic pressure and this is teleologically sound as ACTH is the one pituitary hormone that is essential to life. However, these cells can suffer damage from intracellular tumours, and adrenocortical insu?ciency is not uncommon.
Information about these disorders may be obtained from the Pituitary Foundation.... pituitary-linked disorders
Parasomnias These include medical disorders such as ASTHMA, ANGINA PECTORIS or EPILEPSY which are made worse by sleep, and a range of behavioural alterations which are usually related to a speci?c sleep stage or to a change from one state of sleep to another. Sleepwalking, night terrors, and nightmares are examples.
Insomnia Insomnia is de?ned as a di?culty in initiating or maintaining sleep. It affects around 15 per cent of the population at any one time, and is often due to a poor pre-sleep routine (e.g. taking excessive stimulants such as ca?eine); unsatisfactory sleep due to poor environments such as an uncomfortable bed or a cold or noisy bedroom; anxiety and/or depression; or occasionally to a physical problem – for example, pain – or a medical disorder associated with sleep such as obstructive SLEEP APNOEAS or periodic limb movements.
Excessive daytime sleepiness This is usually due to sleep deprivation caused either by inadequate duration of sleep, or by poor quality of sleep. The individual’s lifestyle is often a cause and modi?cation of this may relieve the problem. Other common causes of excessive daytime sleepiness are depression, obstructive sleep apnoeas, periodic limb movements, excessive alcohol or other drug intake, and, less commonly, NARCOLEPSY.... sleep, disorders of
Ankyloglossia or tongue-tie is a rare disorder in which the frenum or band connecting the lower surface of the tongue to the ?oor of the mouth is so short or tight that the tongue cannot be protruded. Surgery can remedy the defect. It is easy to overdiagnose and is not a common cause of di?culty in feeding at birth or speech defects in infancy.
Gross enlargement of the tongue can make speech indistinct or make swallowing and even breathing di?cult. This is known as macroglossia and may be such that the tongue is constantly protruded from the mouth. The cause may be CONGENITAL, as in severe cases of DOWN’S (DOWN) SYNDROME, or it may occur as a result of ACROMEGALY or be due to abnormal deposits as in AMYLOIDOSIS.
A marked tremor of the tongue when protruded may be seen in various neurological diseases, but may be caused by alcoholism.
After a STROKE involving the motor nerve centre, the control of one side of the tongue musculature will be lost. This will result in the protruded tongue pointing to the side of the body which is paralysed. The sense of taste on one side of the tongue may also be lost in some diseases of the brain and facial nerve.
The presence of fur on the tongue may be obvious and distressing. This is due to thickening of the super?cial layers of the tongue which may appear like hairs which trap food debris and become discoloured. Furring is common during fever and as a result of mouth-breathing and smoking.
In some conditions the tongue may appear dry, red and raw (GLOSSITIS). An in?amed beefy tongue is characteristic of pellagra, a disease caused by de?ciency of NICOTINIC ACID in the diet. A magenta-coloured tongue may be seen when there is a lack of RIBOFLAVIN.
Ulcers of the tongue are similar to those elsewhere in the mouth. The most common are aphthous ulcers which are small, red and painful and last for about ten days. They are associated with stress, mild trauma (such as from jagged teeth), and occasionally with folic acid and vitamin B12 de?ciency. Ulcers of the tongue are sometimes found in patients with chronic bowel disease.... tongue, disorders of
conductive deafness Deafness caused by faulty conduction of sound from the outer to the inner ear.... conduct disorders
Types of dissociative disorder include hysterical amnesia (see hysteria), fugue, depersonalization, and multiple personality.
(See also conversion disorder.)... dissociative disorders
Urinalysis is a simple test in which a urine sample is examined under a microscope for blood cells, pus cells, and casts (cells and mucous material that accumulate in the tubules of the kidneys and pass into the urine).
Urine may be tested for substances, such as proteins, that leak into the urine when the kidneys are damaged.
Kidney function can be assessed by measuring the concentration in the blood of substances, such as urea and creatinine, that the kidneys normally excrete.
Kidney function may also be assessed by kidney imaging techniques.... kidney function tests
Adult kidneys have a smooth exterior, enveloped by a tough ?brous coat that is bound to the kidney only by loose ?brous tissue and by a few blood vessels that pass between it and the kidney. The outer margin of the kidney is convex; the inner is concave with a deep depression, known as the hilum, where the vessels enter. The URETER, which conveys URINE to the URINARY BLADDER, is also joined at this point. The ureter is spread out into an expanded, funnel-like end, known as the pelvis, which further divides up into little funnels known as the calyces. A vertical section through a kidney (see diagram) shows two distinct layers: an outer one, about 4 mm thick, known as the cortex; and an inner one, the medulla, lying closer to the hilum. The medulla consists of around a dozen pyramids arranged side by side, with their base on the cortex and their apex projecting into the calyces of the ureter. The apex of each pyramid is studded with tiny holes, which are the openings of the microscopic uriniferous tubes.
In e?ect, each pyramid, taken together with the portion of cortex lying along its base, is an independent mini-kidney. About 20 small tubes are on the surface of each pyramid; these, if traced up into its substance, repeatedly subdivide so as to form bundles of convoluted tubules, known as medullary rays, passing up towards the cortex. One of these may be traced further back, ending, after a tortuous course, in a small rounded body: the Malpighian corpuscle or glomerulus (see diagram). Each glomerulus and its convoluted tubule is known as a nephron, which constitutes the functional unit of the kidney. Each kidney contains around a million nephrons.
After entering the kidney, the renal artery divides into branches, forming arches where the cortex and medulla join. Small vessels come o? these arches and run up through the cortex, giving o? small branches in each direction. These end in a tuft of capillaries, enclosed in Bowman’s capsule, which forms the end of the uriniferous tubules just described; capillaries with capsule constitute a glomerulus.
After circulating in the glomerulus, the blood leaves by a small vein, which again divides into capillaries on the walls of the uriniferous tubules. From these it is ?nally collected into the renal veins and then leaves the kidney. This double circulation (?rst through the glomerulus and then around the tubule) allows a large volume of ?uid to be removed from the blood in the glomerulus, the concentrated blood passing on to the uriniferous tubule for removal of parts of its solid contents. Other arteries come straight from the arches and supply the medulla direct; the blood from these passes through another set of capillaries and ?nally into the renal veins. This circulation is con?ned purely to the kidney, although small connections by both arteries and veins exist which pass through the capsule and, joining the lumbar vessels, communicate directly with the aorta.
Function The kidneys work to separate ?uid and certain solids from the blood. The glomeruli ?lter from the blood the non-protein portion of the plasma – around 150–200 litres in 24 hours, 99 per cent of which is reabsorbed on passing through the convoluted tubules.
Three main groups of substances are classi?ed according to their extent of uptake by the tubules:
(1) SUBSTANCES ACTIVELY REABSORBED These include amino acids, glucose, sodium, potassium, calcium, magnesium and chlorine (for more information, see under separate entries).
(2) SUBSTANCES DIFFUSING THROUGH THE TUBULAR EPITHELIUM when their concentration in the ?ltrate exceeds that in the PLASMA, such as UREA, URIC ACID and phosphates.
(3) SUBSTANCES NOT RETURNED TO THE BLOOD from the tubular ?uid, such as CREATINE, accumulate in kidney failure, resulting in general ‘poisoning’ known as URAEMIA.... structure each kidney is about 10 cm long,
The most common lipid disorders are the hyperlipidaemias, which are characterized by high levels of lipids in the blood and can cause atherosclerosis and pancreatitis.
There are also some very rare lipid disorders due solely to heredity, such as Tay–Sachs disease.... lipid disorders
Comfrey decoction. 1 heaped teaspoon to cup water gently simmered 5 minutes; strain when cold; 1 cup – to which is added 20 drops Tincture Calendula (Marigold), thrice daily. Fenugreek seeds may be used as an alternative to Comfrey.
Alternative:– Mixture: equal parts liquid extracts: Comfrey, Marigold, St John’s Wort. One teaspoon in water or honey thrice daily.
Tablets/capsules. Fenugreek, St John’s Wort.
Topical. Comfrey, Fenugreek or Horsetail poultice.
Supplements. Vitamin A, C, E. Dolomite, Zinc.
Supportive. Exposure of site to sunlight.
Comfrey. The potential benefit of Comfrey root outweighs possible risk for bone disorders. ... bone disorders
Abscess, Alzheimer’s Disease, anoxia (oxygen starvation), coma, concussion, haemorrhage, Down’s syndrome, epilepsy, tumour, hydrocephalus (water on the brain), meningitis, multiple sclerosis, stroke (rupture of blood vessel), spina bifida, syphilis (general paralysis of the insane), sleepy sickness.
Poor circulation through the brain due to hardening of the arteries: Ginkgo, Ginseng. Ginseng stimulates the hypothalmic/pituitary axis of the brain and favourably influences its relationship with the adrenal glands.
Congestion of the brain – Cowslip (Boerwicke). Irritability of brain and spine – Hops. Oats. Inflammation of the brain (encephalitis) as in viral infection, poliomyelitis, rabies, sleepy sickness, etc: Echinacea, Passion flower, Skullcap and Lobelia. Gelsemium acts as a powerful relaxant in the hands of a practitioner: Tincture BPC (1973): dose 0.3ml.
Brain storm from hysteria, locomotor ataxia, etc – Liquid Extract Lobelia: 5ml teaspoon in water when necessary (Dr Jentzsch, 1915, Ellingwood) Supplement with Zinc, Vitamins C and E.
Blood clot, thrombosis: Yarrow. Neurasthenia: Oats, Basil, Hops.
Brain fag and jet-lag: Chamomile, Skullcap, Oats, Ginseng, Ginkgo.
Tumour may be present years before manifesting: Goldenseal.
Mental state: depression, anxiety, schizophrenia.
Tea. Formula. Skullcap, Gotu Kola and German Chamomile; equal parts. 1 heaped teaspoon to each cup water gently simmered 10 minutes. Strain. 1 cup thrice daily.
Unspecified tensive state. Formula. Tinctures. Hops 1; Passion flower 2; Valerian 2. Dose: 2 teaspoons thrice daily until diagnosis is concluded.
Unspecified torpor. Formula. Tinctures. Ginseng 1; Kola 1; Capsicum quarter. 2 teaspoons in water thrice daily until diagnosis is concluded.
Brain weakness in the elderly: Ginkgo. See: ALZHEIMER’S DISEASE.
Fluid on the brain: see HYDROCEPHALUS.
Abscess of the brain: see ABSCESS.
Brain restoratives. Black Haw, True Unicorn root, Galangal, Oats, Oatstraw, False Unicorn root, Kola, Hops. Vitamin B6. Magnesium.
Cerebral thrombosis. See entry.
Note: Cold water may help victims to survive: rapid loss of body heat protects the brain. (Child Health Department, University of Wales)
Treatment by or in liaison with general medical practitioner or hospital specialist. ... brain disorders
Formula. Corn Silk 3; Plantain (Plantago major L) 2; Golden Rod 1; Hydrangea 1; Valerian half. Dosage: thrice daily before meals. Liquid Extracts: 1 teaspoon. Tinctures: 2 teaspoons. Powders: two 00 capsules or one-third teaspoon. This may be used as a basic combination to be adapted to a changing clinical picture.
Treatment by a general medical practitioner or oncologist. ... cancer – kidney
Other causes requiring specific treatment are: thickening and narrowing of blood vessels, diabetes, Buerger’s disease, Raynaud’s disease (spasm of the arterioles and veins), arteritis. See appropriate entries.
As a protection against these diseases Garlic becomes increasingly popular. Control of blood fats through diet and exercise necessary.
Alternatives. Cayenne, Ginger, Hawthorn berries, Horseradish, Mustard, Prickly Ash bark, Buckwheat, Dandelion, Lime flowers, Mistletoe, Rosemary, Yarrow, Ginkgo.
Tea: Lime flowers, Hawthorn berries, Yarrow. Equal parts. Mix. Ginger, quarter part (or pinch of Red Pepper). Mix. 1-2 teaspoons to each cup water. Bring to boil. Remove vessel when boiling point is reached. Dose: 1 cup 2-3 times daily.
Tablets or capsules: Prickly Ash, Hawthorn, Mistletoe, Ginkgo.
Formula. Hawthorn 2; Yarrow 2; Prickly Ash 1; Ginger quarter. Dose: Powders: 500mg (two 00 capsules or one-third teaspoon). Liquid extracts: 1 teaspoon. Tinctures 2 teaspoons 2-3 times daily.
Practitioner. Liquid extracts: Hawthorn 2; Lily of the Valley 2; Prickly Ash 1; Tincture Capsicum (one- tenth part). Dose: 30-60 drops in water or honey, 2-3 times daily.
Diet and Supplements. See: DIET – HEART AND CIRCULATION. ... circulatory disorders
Accept. Goat’s milk, yoghurt, eggs – twice weekly. The high potassium and low salt content of bananas help reduce itching. Lecithin. Oily fish. Purslane is a non-fish source of EPA and suitable for the vegetarian approach. Cottage cheese. Pumpkin seeds as a source of zinc. Dandelion coffee. Artichoke: such as Schoenenberger plant juice. Salad dressing: emulsify 1 teaspoon Cider vinegar to each 2 teaspoons safflower seed oil.
Reject: Fried and greasy foods, pastries, chocolates, sweets, ice cream, spicy foods, seasoning, sausage meats, white flour products, white sugar products, alcoholic drinks, meat from the pig (ham, pork, bacon), peppers, horseradish, condiments. Powdered kelp in place of salt, powdered garlic or celery.
Foods known to contain artificial colours and preservatives. All soft drinks, except those made at home from fresh fruits or raw vegetables; coffee, strong tea, oranges. Cola drinks, chocolate, milk, cream, cheese, whey.
Supplement. Beta carotene.
Study. A flare-up can be caused by nuts, jams, fruits, artificially coloured or flavoured foods. (British Journal of Dermatology, 110, 457, (1984)) ... diet - skin disorders
A genetic defect causes congenital adrenal hyperplasia, in which the adrenal cortex is unable to make sufficient hydrocortisone and aldosterone, and androgens are produced in excess. In adrenal failure, there is also deficient production of hormones by the adrenal cortex; if due to disease of the adrenal glands, it is called Addison’s disease. Adrenal tumours are rare and generally lead to excess hormone production.
In many cases, disturbed activity of the adrenal glands is caused, not by disease of the glands themselves, but by an increase or decrease in the blood level of hormones that influence the action of the adrenal glands. For example, hydrocortisone production by the adrenal cortex is controlled by ACTH, which is secreted by the pituitary gland. Pituitary disorders can disrupt production of hydrocortisone.... adrenal gland disorders
High alcohol consumption increases the risk of cancers of the mouth, tongue, pharynx (throat), larynx (voice box), and oesophagus, especially if combined with smoking. Incidence of liver cancer, as well as the liver diseases alcoholic hepatitis and cirrhosis, is higher among alcoholics. High alcohol consumption increases the risk of cardiomyopathy, hypertension, and stroke. Alcohol irritates the digestive tract and may cause gastritis. Heavy drinking in pregnancy increases the risk of miscarriage and fetal alcohol syndrome. Alcoholics are more likely to suffer from anxiety and depression and to develop dementia.
Many alcoholics have a poor diet and are prone to diseases caused by nutritional deficiency, particularly of thiamine (see vitamin B complex). Severe thiamine deficiency, called beriberi, disturbs nerve function, causing cramps, numbness, and weakness in the legs and hands. Its effects on the brain can cause confusion, disturbances of speech and gait, and eventual coma (see Wernicke– Korsakoff syndrome). Severe thiamine deficiency can also cause heart failure.
A prolonged high level of alcohol in the blood and tissues can disturb body chemistry, resulting in hypoglycaemia (reduced glucose in the blood) and hyperlipidaemia (increased fat in the blood).
These may damage the heart, liver, blood vessels, and brain; irreversible damage may cause premature death.... alcohol-related disorders
Rarely, the anus may fail to develop normally and surgical treatment is needed (see anus, imperforate).
In anal stenosis, the anus is too narrow to allow the passage of faeces.
Anal fissures originate from tears in the lining of the anus, usually as a result of straining to pass faeces.
Cancer of the skin around the anus is rare (see anus, cancer of).
Haemorrhoids are enlarged blood vessels under the anal lining.
An anal fistula is an abnormal channel connecting the anal canal with the skin surrounding the anus.
Itching of the anus is common and may be due to haemorrhoids or other disorders such as threadworm infestation.... anus, disorders of
In generalized anxiety disorder, there is persistent tension and apprehension that has no specific focus or cause, together with physical or psychological symptoms that disrupt normal activity. Panic disorders are characterized by sudden attacks of extreme, unreasonable anxiety. Phobias are irrational fears, such as the fear of open spaces or spiders, that lead to avoidance of certain situations or objects.
Counselling, psychotherapy, and group or individual cognitive–behaviour therapy are used to treat anxiety disorders.
Antianxiety drugs (especially benzodiazepine drugs) may be used for shortterm treatment but are addictive.... anxiety disorders
Atherosclerosis, in which fat deposits build up on artery walls, is the most common arterial disease.
It can involve arteries throughout the body, including the brain (see cerebrovascular disease), heart (see coronary artery disease), and legs (see peripheral vascular disease).
Atherosclerosis is the main type of arteriosclerosis, a group of disorders that cause thickening and loss of elasticity of artery walls.
Hypertension is another common cause of thickening and narrowing of arteries, and it increases the risk of a stroke or kidney failure.
Arteritis is inflammation of artery walls that causes narrowing and sometimes blockage.
Aneurysm is ballooning of an artery wall caused by the pressure of blood flowing through a weakened area.
Thrombosis occurs when a blood clot forms in a blood vessel, causing obstruction of the blood flow.
Blockage of an artery by a fragment of blood clot or other material travelling in the circulation is called an embolism.
Raynaud’s disease is a disorder involving intermittent spasm of small arteries in the hands and feet, usually due to cold.... arteries, disorders of
Disturbed bladder control can also result from nerve degeneration in conditions such as diabetes mellitus, multiple sclerosis, or dementia. An unstable or irritable bladder is a common condition and is sometimes associated with a urinary tract infection or prolapse of the uterus. Tension or anxiety can cause frequent urination. In children, delayed bladder control (see enuresis) most often results from delayed maturation of the nervous system.... bladder, disorders of
Coagulation disorders are usually due a deficiency of or abnormality in the enzymes (coagulation factors) involved in blood clotting. Defects may be congenital or acquired later in life. The
main congenital coagulation defects are von Willebrand’s disease, haemophilia, and Christmas disease.
Acquired defects of coagulation factors may develop at any age due to severe liver disease, digestive system disorders that prevent the absorption of vitamin K (needed to make certain coagulation factors), or the use of anticoagulant drugs. Disseminated intravascular coagulation (DIC) is an acquired disorder that is both complex and serious. It may be the result of underlying infection or cancer. In this condition, platelets accumulate and clots form within small blood vessels; coagulation factors are used up faster than they can be replaced, and severe bleeding may result.
Coagulation disorders are treated by replacement of the missing factor, factors extracted from fresh blood, or fresh frozen plasma. Genetically engineered factors may be used. Anticoagulants are sometimes used to suppress excess clotting activity in.
Thrombocytopenia, which results from insufficient platelets in the blood, produces surface bleeding into the skin and gums and multiple small bruises. Platelet defects may be inherited, associated with the use of certain drugs (including aspirin), or a complication of certain bone marrow disorders such as myeloid leukaemia. Treatment consists of platelet transfusions. Rarely, abnormal bleeding is caused by a bloodvessel defect or scurvy. Elderly people and patients on long-term courses of corticosteroid drugs may suffer mild abnormal bruising due to loss of skin support to the smallest blood vessels.
Treatment is rarely required.... bleeding disorders
Reduced oxygen supply may occur at birth, causing cerebral palsy. Later in life, cerebral hypoxia can result from choking or from arrest of breathing and heartbeat. From middle age onwards, cerebrovascular disease is the most important cause of brain disorder. If an artery within the brain becomes blocked or ruptures, leading to haemorrhage, the result is a stroke. The brain may also be damaged by a blow to the head see head injury).
Infection within the brain (encephalitis) may be due to viral infection. Infection of the membranes surrounding the brain (meningitis) is generally due to bacterial infection. Creutzfeldt–Jakob disease is a rare, fatal brain disease associated with an infective agent called a prion which, in some cases, has been linked with (bovine spongiform encephalopathy), a disease in cattle.
Multiple sclerosis is a progressive disease of the brain and spinal cord. Degenerative brain diseases include Alzheimer’s disease and Parkinson’s disease. Emotional or behavioural disorders are generally described as psychiatric illnesses; but the distinction between neurological and psychiatric disorders is now much less clear.... brain, disorders of
A genetic disorder may impair the thyroid’s ability to secrete hormones and goitre may result. Thyroid infection is uncommon and leads to thyroiditis. Viral infection can cause extreme pain and temporary hyperthyroidism. Hormonal changes during puberty or pregnancy may cause a degree of goitre temporarily. Hyperthyroidism due to excessive production of by the pituitary gland is rare but can occur as a result of a pituitary tumour.
Because iodine is necessary for the production of thyroid hormone, its deficiency may lead to goitre. Severe iodine deficiency in children may cause myxoedema. (See also thyroid cancer.)
thyroid hormones The 3 hormones produced by the thyroid gland are thyroxine (T4) and triiodothyronine (T3), which regulate metabolism, and calcitonin, which helps to regulate calcium levels in the body.... thyroid gland, disorders of
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