Thyrotoxicosis Health Dictionary

SIMPLE GOITRE A benign enlargement of the THYROID GLAND with normal production of hormone. It is ENDEMIC in certain geographical areas where there is IODINE de?ciency. Thus, if iodine intake is de?cient, the production of thyroid hormone is threatened and the anterior PITUITARY GLAND secretes increased amounts of thyrotrophic hormone with consequent overgrowth of the thyroid gland. Simple goitres in non-endemic areas may occur at puberty, during pregnancy and at the menopause, which are times of increased demand for thyroid hormone. The only e?ective treament is thyroid replacement therapy to suppress the enhanced production of thyrotrophic hormone. The prevalence of endemic goitre can be, and has been, reduced by the iodinisation of domestic salt in many countries. NODULAR GOITRES do not respond as well as the di?use goitres to THYROXINE treatment. They are usually the result of alternating episodes of hyperplasia and involution which lead to permanent thyroid enlargement. The only e?ective way of curing a nodular goitre is to excise it, and THYROIDECTOMY should be recommended if the goitre is causing pressure symptoms or if there is a suspicion of malignancy. LYMPHADENOID GOITRES are due to the production of ANTIBODIES against antigens (see ANTIGEN) in the thyroid gland. They are an example of an autoimmune disease. They tend to occur in the third and fourth decade and the gland is much ?rmer than the softer gland of a simple goitre. Lymphadenoid goitres respond to treatment with thyroxine. TOXIC GOITRES may occur in thyrotoxicosis (see below), although much less frequently autonomous nodules of a nodular goitre may be responsible for the increased production of thyroxine and thus cause thyrotoxicosis. Thyrotoxicosis is also an autoimmune disease in which an antibody is produced that stimulates the thyroid to produce excessive amounts of hormone, making the patient thyrotoxic.

Rarely, an enlarged gland may be the result of cancer in the thyroid.

Treatment A symptomless goitre may gradually disappear or be so small as not to merit treatment. If the goitre is large or is causing the patient di?culty in swallowing or breathing, it may need surgical removal by partial or total thyroidectomy. If the patient is de?cient in iodine, ?sh and iodised salt should be included in the diet.

Hyperthyroidism is a common disorder affecting 2–5 per cent of all females at some time in their lives. The most common cause – around 75 per cent of cases – is thyrotoxicosis (see below). An ADENOMA (or multiple adenomas) or nodules in the thyroid also cause hyperthyroidism. There are several other rare causes, including in?ammation caused by a virus, autoimune reactions and cancer. The symptoms of hyperthyroidism affect many of the body’s systems as a consequence of the much-increased metabolic rate.

Thyrotoxicosis is a syndrome consisting of di?use goitre (enlarged thyroid gland), over-activity of the gland and EXOPHTHALMOS (protruding eyes). Patients lose weight and develop an increased appetite, heat intolerance and sweating. They are anxious, irritable, hyperactive, suffer from TACHYCARDIA, breathlessness and muscle weakness and are sometimes depressed. The hyperthyroidism is due to the production of ANTIBODIES to the TSH receptor (see THYROTROPHIN-STIMULATING HORMONE (TSH)) which stimulate the receptor with resultant production of excess thyroid hormones. The goitre is due to antibodies that stimulate the growth of the thyroid gland. The exoph-

thalmos is due to another immunoglobulin called the ophthalmopathic immunoglobulin, which is an antibody to a retro-orbital antigen on the surface of the retro-orbital EYE muscles. This provokes in?ammation in the retro-orbital tissues which is associated with the accumulation of water and mucopolysaccharide which ?lls the orbit and causes the eye to protrude forwards.

Although thyrotoxicosis may affect any age-group, the peak incidence is in the third decade. Females are affected ten times as often as males; the prevalence in females is one in 500. As with many other autoimmune diseases, there is an increased prevalence of autoimmune thyroid disease in the relatives of patients with thyrotoxicosis. Some of these patients may have hypothyroidism (see below) and others, thyrotoxicosis. Patients with thyrotoxicosis may present with a goitre or with the eye signs or, most commonly, with the symptoms of excess thyroid hormone production. Thyroid hormone controls the metabolic rate of the body so that the symptoms of hyperthyroidism are those of excess metabolism.

The diagnosis of thyrotoxicosis is con?rmed by the measurement of the circulating levels of the two thyroid hormones, thyroxine and TRIIODOTHYRONINE.

Treatment There are several e?ective treatments for thyrotoxicosis. ANTITHYROID DRUGS These drugs inhibit the iodination of tyrosine and hence the formation of the thyroid hormones. The most commonly used drugs are carbimazole and propylthiouricil: these will control the excess production of thyroid hormones in virtually all cases. Once the patient’s thyroid is functioning normally, the dose can be reduced to a maintenance level and is usually continued for two years. The disadvantage of antithyroid drugs is that after two years’ treatment nearly half the patients will relapse and will then require more de?nitive therapy. PARTIAL THYROIDECTOMY Removal of three-quarters of the thyroid gland is e?ective treatment of thyrotoxicosis. It is the treatment of choice in those patients with large goitres. The patient must however be treated with medication so that they are euthyroid (have a normally functioning thyroid) before surgery is undertaken, or thyroid crisis and cardiac arrhythmias may complicate the operation. RADIOACTIVE IODINE THERAPY This has been in use for many years, and is an e?ective means of controlling hyperthyroidism. One of the disadvantages of radioactive iodine is that the incidence of hypothyroidism is much greater than with other forms of treatment. However, the management of hypothyroidism is simple and requires thyroxine tablets and regular monitoring for hypothyroidism. There is no evidence of any increased incidence of cancer of the thyroid or LEUKAEMIA following radio-iodine therapy. It has been the pattern in Britain to reserve radio-iodine treatment to those over the age of 35, or those whose prognosis is unlikely to be more than 30 years as a result of cardiac or respiratory disease. Radioactive iodine treatment should not be given to a seriously thyrotoxic patient. BETA-ADRENOCEPTOR-BLOCKING DRUGS Usually PROPRANOLOL HYDROCHLORIDE: useful for symptomatic treatment during the ?rst 4–8 weeks until the longer-term drugs have reduced thyroid activity.

Hypothyroidism A condition resulting from underactivity of the thyroid gland. One form, in which the skin and subcutaneous tissues thicken and result in a coarse appearance, is called myxoedema. The thyroid gland secretes two hormones – thyroxine and triiodothyronine – and these hormones are responsible for the metabolic activity of the body. Hypothyroidism may result from developmental abnormalities of the gland, or from a de?ciency of the enzymes necessary for the synthesis of the hormones. It may be a feature of endemic goitre and retarded development, but the most common cause of hypothyroidism is the autoimmune destruction of the thyroid known as chronic thyroiditis. It may also occur as a result of radio-iodine treatment of thyroid overactivity (see above) and is occasionally secondary to pituitary disease in which inadequate TSH production occurs. It is a common disorder, occurring in 14 per 1,000 females and one per 1,000 males. Most patients present between the age of 30 and 60 years.

Symptoms As thyroid hormones are responsible for the metabolic rate of the body, hypothyroidism usually presents with a general sluggishness: this affects both physical and mental activities. The intellectual functions become slow, the speech deliberate and the formation of ideas and the answers to questions take longer than in healthy people. Physical energy is reduced and patients frequently complain of lethargy and generalised muscle aches and pains. Patients become intolerant of the cold and the skin becomes dry and swollen. The LARYNX also becomes swollen and gives rise to a hoarseness of the voice. Most patients gain weight and develop constipation. The skin becomes dry and yellow due to the presence of increased carotene. Hair becomes thinned and brittle and even baldness may develop. Swelling of the soft tissues may give rise to a CARPAL TUNNEL SYNDROME and middle-ear deafness. The diagnosis is con?rmed by measuring the levels of thyroid hormones in the blood, which are low, and of the pituitary TSH which is raised in primary hypothyroidism.

Treatment consists of the administration of thyroxine. Although tri-iodothyronine is the metabolically active hormone, thyroxine is converted to tri-iodothyronine by the tissues of the body. Treatment should be started cautiously and slowly increased to 0·2 mg daily – the equivalent of the maximum output of the thyroid gland. If too large a dose is given initially, palpitations and tachycardia are likely to result; in the elderly, heart failure may be precipitated.

Congenital hypothyroidism Babies may be born hypothyroid as a result of having little or no functioning thyroid-gland tissue. In the developed world the condition is diagnosed by screening, all newborn babies having a blood test to analyse TSH levels. Those found positive have a repeat test and, if the diagnosis is con?rmed, start on thyroid replacement therapy within a few weeks of birth. As a result most of the ill-effects of cretinism can be avoided and the children lead normal lives.

Thyroiditis In?ammation of the thyroid gland. The acute form is usually caused by a bacterial infection elsewhere in the body: treatment with antibiotics is needed. Occasionally a virus may be the infectious agent. Hashimoto’s thyroiditis is an autoimmune disorder causing hypothyroidism (reduced activity of the gland). Subacute thyroiditis is in?ammation of unknown cause in which the gland becomes painful and the patient suffers fever, weight loss and malaise. It sometimes lasts for several months but is usually self-limiting.

Thyrotoxic adenoma A variety of thyrotoxicosis (see hyperthyroidism above) in which one of the nodules of a multinodular goitre becomes autonomous and secretes excess thyroid hormone. The symptoms that result are similar to those of thyrotoxicosis, but there are minor di?erences.

Treatment The ?rst line of treatment is to render the patient euthyroid by treatment with antithyroid drugs. Then the nodule should be removed surgically or destroyed using radioactive iodine.

Thyrotoxicosis A disorder of the thyroid gland in which excessive amounts of thyroid hormones are secreted into the bloodstream. Resultant symptoms are tachycardia, tremor, anxiety, sweating, increased appetite, weight loss and dislike of heat. (See hyperthyroidism above.)... goitre

Exophthalmos, or PROPTOSIS, refers to forward displacement of the eyeball and must be distinguished from retraction of the eyelids, which causes an illusion of exophthalmos. Lid retraction usually results from activation of the autonomic nervous sytem. Exophthalmos is a more serious disorder caused by in?ammatory and in?ltrative changes in the retro-orbital tissues and is essentially a feature of Graves’ disease, though it has been described in chronic thyroiditis (see THYROID GLAND, DISEASES OF). Exophthalmos commonly starts shortly after the development of thyrotoxicosis but may occur months or even years after hyperthyroidism has been successfully treated. The degree of exophthalmos is not correlated with the severity of hyperthyroidism even when their onset is simultaneous. Some of the worst examples of endocrine exophthalmos occur in the euthyroid state and may appear in patients who have never had thyrotoxicosis; this disorder is named ophthalmic Graves’ disease. The exophthalmos of Graves’ disease is due to autoimmunity (see IMMUNITY). Antibodies to surface antigens on the eye muscles are produced and this causes an in?ammatory reaction in the muscle and retroorbital tissues.

Exophthalmos may also occur as a result of OEDEMA, injury, cavernous venous THROMBOSIS or a tumour at the back of the eye, pushing the eyeball forwards. In this situation it is always unilateral.... exophthalmos

A ?ne involuntary movement. Tremors may be seen in projecting parts like the hands, head and tongue, or they may involve muscles. Coarse tremors, which prevent a person from drinking a glass of water without spilling it, are found in MULTIPLE SCLEROSIS (MS) and in CHOREA; somewhat ?ner tremors, which produce trembling of the hands or tongue when they are stretched out, are caused by alcoholism (see ALCOHOL) and other forms of poisoning, by PARKINSONISM, and by the weakness which follows some acute disease or characterises old age. A ?ne tremor of the outstretched ?ngers is a characteristic of thyrotoxicosis (see under THYROID GLAND, DISEASES OF); very ?ne tremors, visible in the muscles of face or limbs and known as ?brillary tremors, are present in general paralysis of the insane (see SYPHILIS), and in progressive muscular atrophy or wasting palsy. Tremors may occur at rest and disappear on movement as in Parkinsonism, or they may occur only on movement (intention tremors) as in cerebellar disease.... tremor

Excessive sweating, which may be localized (affecting only the armpits, feet, palms, or face) or affect all body areas supplied by sweat glands.

Excessive sweating may be caused by hot weather, exercise, or anxiety. In some cases it is due to an infection, thyrotoxicosis, hypoglycaemia, or a nervous system disorder. Usually, the disorder has no known cause, and begins at puberty, disappearing by the mid-20s or early 30s.

If hyperhidrosis is persistent and cannot be controlled by antiperspirants, surgery may be considered to destroy the nerve centres that control sweating.... hyperhidrosis

Appetite is the craving for the food necessary to maintain the body and to supply it with suf?cient energy to carry on its functions. The ultimate cause of appetite is a question of supply and demand in the muscles and various organs, but the proximate cause is doubtful. Unlike hunger, it is probably an acquired, rather than an inborn, sensation. Whatever other factors may be concerned, the tone of the STOMACH is of importance. Signi?cant factors in stimulating appetite are anticipation and the sight and smell of well-cooked food. Individuals who eat unsuitable substances such as faeces are described as suffering from pica, which occurs sometimes during pregnancy, in children, and often in mental disorders. The two chief disorders, however, are excessive increase of appetite, and diminution or loss of appetite (see also EATING DISORDERS).

Excessive appetite may simply be a bad habit, due to habitual over-indulgence in good food and resulting in GOUT, OBESITY, etc. – according to the other habits and constitution of the person. It may also be a sign of DIABETES MELLITUS or thyrotoxicosis (see under THYROID GLAND, DISEASES OF).

Diminished appetite is a sign common to almost all diseases causing general weakness, because the activity of the stomach and the secretion of gastric juice fail early when vital power is low. It is the most common sign of DYSPEPSIA due to gastritis, and of cancer of the stomach. In some cases it is a manifestation of stress or strain such as domestic worry or dif?culties at work. Indeed, appetite seems to be particularly susceptible to emotional disturbances, as is evidenced by the linked conditions of BULIMIA (pathological overeating) and anorexia nervosa (pathological dieting) – see also EATING DISORDERS.... appetite

Also called beta blockers, these drugs interrupt the transmission of neuronal messages via the body’s adrenergic receptor sites. In the HEART these are called beta1 (cardioselective) receptors. Another type – beta2 (non-cardioselective) receptors – is sited in the airways, blood vessels, and organs such as the eye, liver and pancreas. Cardioselective beta blockers act primarily on beta1 receptors, whereas non-cardioselective drugs act on both varieties, beta1 and beta2. (The neurotransmissions interrupted at the beta-receptor sites through the body by the beta blockers are initiated in the ADRENAL GLANDS: this is why these drugs are sometimes described as beta-adrenergic-blocking agents.)

They work by blocking the stimulation of beta adrenergic receptors by the neurotransmitters adrenaline and noradrenaline, which are produced at the nerve endings of that part of the SYMPATHETIC NERVOUS SYSTEM – the autonomous (involuntary) network

– which facilitates the body’s reaction to anxiety, stress and exercise – the ‘fear and ?ight’ response.

Beta1 blockers reduce the frequency and force of the heartbeat; beta2 blockers prevent vasodilation (increase in the diameter of blood vessels), thus in?uencing the patient’s blood pressure. Beta1 blockers also affect blood pressure, but the mechanism of their action is unclear. They can reduce to normal an abnormally fast heart rate so the power of the heart can be concomitantly controlled: this reduces the oxygen requirements of the heart with an advantageous knock-on e?ect on the respiratory system. These are valuable therapeutic effects in patients with ANGINA or who have had a myocardial infarction (heart attack – see HEART, DISEASES OF), or who suffer from HYPERTENSION. Beta2 blockers reduce tremors in muscles elsewhere in the body which are a feature of anxiety or the result of thyrotoxicosis (an overactive thyroid gland – see under THYROID GLAND, DISEASES OF). Noncardioselective blockers also reduce the abnormal pressure caused by the increase in the ?uid in the eyeball that characterises GLAUCOMA.

Many beta-blocking drugs are now available; minor therapeutic di?erences between them may in?uence the choice of a drug for a particular patient. Among the common drugs are:

Primarily cardioselective	Non-cardioselective
Acebutolol	Labetalol
Atenolol	Nadolol
Betaxolol	Oxprenolol
Celiprolol	Propanolol
Metoprolol	Timolol

These powerful drugs have various side-effects and should be prescribed and monitored with care. In particular, people who suffer from asthma, bronchitis or other respiratory problems may develop breathing diffculties. Long-term treatment with beta blockers should not be suddenly stopped, as this may precipitate a severe recurrence of the patient’s symptoms – including, possibly, a sharp rise in blood pressure. Gradual withdrawal of medication should mitigate untoward effects.... beta-adrenoceptor-blocking drugs

Bone is not an inert sca?olding for the human body. It is a living, dynamic organ, being continuously remodelled in response to external mechanical and chemical in?uences and acting as a large reservoir for calcium and phosphate. It is as susceptible to disease as any other organ, but responds in a way rather di?erent from the rest of the body.

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

Organs whose function it is to secrete into the blood or lymph, substances known as HORMONES. These play an important part in general changes to or the activities of other organs at a distance. Various diseases arise as the result of defects or excess in the internal secretions of the di?erent glands. The chief endocrine glands are:

Adrenal glands These two glands, also known as suprarenal glands, lie immediately above the kidneys. The central or medullary portion of the glands forms the secretions known as ADRENALINE (or epinephrine) and NORADRENALINE. Adrenaline acts upon structures innervated by sympathetic nerves. Brie?y, the blood vessels of the skin and of the abdominal viscera (except the intestines) are constricted, and at the same time the arteries of the muscles and the coronary arteries are dilated; systolic blood pressure rises; blood sugar increases; the metabolic rate rises; muscle fatigue is diminished. The super?cial or cortical part of the glands produces steroid-based substances such as aldosterone, cortisone, hydrocortisone, and deoxycortone acetate, for the maintenance of life. It is the absence of these substances, due to atrophy or destruction of the suprarenal cortex, that is responsible for the condition known as ADDISON’S DISEASE. (See CORTICOSTEROIDS.)

Ovaries and testicles The ovary (see OVARIES) secretes at least two hormones – known, respectively, as oestradiol (follicular hormone) and progesterone (corpus luteum hormone). Oestradiol develops (under the stimulus of the anterior pituitary lobe – see PITUITARY GLAND below, and under separate entry) each time an ovum in the ovary becomes mature, and causes extensive proliferation of the ENDOMETRIUM lining the UTERUS, a stage ending with shedding of the ovum about 14 days before the onset of MENSTRUATION. The corpus luteum, which then forms, secretes both progesterone and oestradiol. Progesterone brings about great activity of the glands in the endometrium. The uterus is now ready to receive the ovum if it is fertilised. If fertilisation does not occur, the corpus luteum degenerates, the hormones cease acting, and menstruation takes place.

The hormone secreted by the testicles (see TESTICLE) is known as TESTOSTERONE. It is responsible for the growth of the male secondary sex characteristics.

Pancreas This gland is situated in the upper part of the abdomen and, in addition to the digestive enzymes, it produces INSULIN within specialised cells (islets of Langerhans). This controls carbohydrate metabolism; faulty or absent insulin production causes DIABETES MELLITUS.

Parathyroid glands These are four minute glands lying at the side of, or behind, the thyroid (see below). They have a certain e?ect in controlling the absorption of calcium salts by the bones and other tissues. When their secretion is defective, TETANY occurs.

Pituitary gland This gland is attached to the base of the brain and rests in a hollow on the base of the skull. It is the most important of all endocrine glands and consists of two embryologically and functionally distinct lobes.

The function of the anterior lobe depends on the secretion by the HYPOTHALAMUS of certain ‘neuro-hormones’ which control the secretion of the pituitary trophic hormones. The hypothalamic centres involved in the control of speci?c pituitary hormones appear to be anatomically separate. Through the pituitary trophic hormones the activity of the thyroid, adrenal cortex and the sex glands is controlled. The anterior pituitary and the target glands are linked through a feedback control cycle. The liberation of trophic hormones is inhibited by a rising concentration of the circulating hormone of the target gland, and stimulated by a fall in its concentration. Six trophic (polypeptide) hormones are formed by the anterior pituitary. Growth hormone (GH) and prolactin are simple proteins formed in the acidophil cells. Follicle-stimulating hormone (FSH), luteinising hormone (LH) and thyroid-stimulating hormone (TSH) are glycoproteins formed in the basophil cells. Adrenocorticotrophic hormone (ACTH), although a polypeptide, is derived from basophil cells.

The posterior pituitary lobe, or neurohypophysis, is closely connected with the hypothalamus by the hypothalamic-hypophyseal tracts. It is concerned with the production or storage of OXYTOCIN and vasopressin (the antidiuretic hormone).

PITUITARY HORMONES Growth hormone, gonadotrophic hormone, adrenocorticotrophic hormone and thyrotrophic hormones can be assayed in blood or urine by radio-immunoassay techniques. Growth hormone extracted from human pituitary glands obtained at autopsy was available for clinical use until 1985, when it was withdrawn as it is believed to carry the virus responsible for CREUTZFELDT-JAKOB DISEASE (COD). However, growth hormone produced by DNA recombinant techniques is now available as somatropin. Synthetic growth hormone is used to treat de?ciency of the natural hormone in children and adults, TURNER’S SYNDROME and chronic renal insu?ciency in children.

Human pituitary gonadotrophins are readily obtained from post-menopausal urine. Commercial extracts from this source are available and are e?ective for treatment of infertility due to gonadotrophin insu?ciency.

The adrenocorticotrophic hormone is extracted from animal pituitary glands and has been available therapeutically for many years. It is used as a test of adrenal function, and, under certain circumstances, in conditions for which corticosteroid therapy is indicated (see CORTICOSTEROIDS). The pharmacologically active polypeptide of ACTH has been synthesised and is called tetracosactrin. Thyrotrophic hormone is also available but it has no therapeutic application.

HYPOTHALAMIC RELEASING HORMONES which affect the release of each of the six anterior pituitary hormones have been identi?ed. Their blood levels are only one-thousandth of those of the pituitary trophic hormones. The release of thyrotrophin, adrenocorticotrophin, growth hormone, follicle-stimulating hormone and luteinising hormone is stimulated, while release of prolactin is inhibited. The structure of the releasing hormones for TSH, FSH-LH, GH and, most recently, ACTH is known and they have all been synthesised. Thyrotrophin-releasing hormone (TRH) is used as a diagnostic test of thyroid function but it has no therapeutic application. FSH-LH-releasing hormone provides a useful diagnostic test of gonadotrophin reserve in patients with pituitary disease, and is now used in the treatment of infertility and AMENORRHOEA in patients with functional hypothalamic disturbance. As this is the most common variety of secondary amenorrhoea, the potential use is great. Most cases of congenital de?ciency of GH, FSH, LH and ACTH are due to defects in the hypothalamic production of releasing hormone and are not a primary pituitary defect, so that the therapeutic implication of this synthesised group of releasing hormones is considerable.

GALACTORRHOEA is frequently due to a microadenoma (see ADENOMA) of the pituitary. DOPAMINE is the prolactin-release inhibiting hormone. Its duration of action is short so its therapeutic value is limited. However, BROMOCRIPTINE is a dopamine agonist with a more prolonged action and is e?ective treatment for galactorrhoea.

Thyroid gland The functions of the thyroid gland are controlled by the pituitary gland (see above) and the hypothalamus, situated in the brain. The thyroid, situated in the front of the neck below the LARYNX, helps to regulate the body’s METABOLISM. It comprises two lobes each side of the TRACHEA joined by an isthmus. Two types of secretory cells in the gland – follicular cells (the majority) and parafollicular cells – secrete, respectively, the iodine-containing hormones THYROXINE (T4) and TRI-IODOTHYRONINE (T3), and the hormone CALCITONIN. T3 and T4 help control metabolism and calcitonin, in conjunction with parathyroid hormone (see above), regulates the body’s calcium balance. De?ciencies in thyroid function produce HYPOTHYROIDISM and, in children, retarded development. Excess thyroid activity causes thyrotoxicosis. (See THYROID GLAND, DISEASES OF.)... endocrine glands

The physical symptoms often associated with Grave’s disease or thyrotoxicosis, with an inflamed, sometimes enlarged thyroid gland and, most noticeably, protruding eyes.... goiter, exophthalmic

A condition in which the whole of the THYROID GLAND is di?usely enlarged and ?rm. It is one of the diseases produced by AUTOIMMUNITY. The enlargement is due to di?use in?ltration of lymphocytes and increase of ?brous tissue. This form of GOITRE appears in middle-aged women, does not give rise to symptoms of thyrotoxicosis (see THYROID GLAND, DISEASES OF – Thyrotoxicosis), and tends to produce myxoedema (see THYROID GLAND, DISEASES OF – Hypothyroidism).... hashimoto’s disease

Wall. ex Stapf.

Family: Ephedraceae.

Habitat: The drier regions of the temperate and alpine Himalayas from Kashmir to Sikkim from 2,350 to 5,350 m.

English: Ephedra (Ephedra sinica Stapf.)

Ayurvedic: Soma, Soma-valli (substitute).

Folk: Asmaaniyaa, Budaagur (Punjab); Tipat, Traani (Himalayan region).

Action: Circulatory stimulant, bron- chodilator, vasodilator, antiallergic, antiasthmatic (usualy given with expectorants), diaphoretic. Not prescribed with antidepressants.

Key application: Ephedra sinica— in diseases of the respiratory tract and mild bronchospasms. Also in acute coryza, allergic rhinitis and sinusitis. (German Commission E.) In the treatment of nasal congestion due to hay fever, allergic rhinitis, acute coryza, cold, sinusitis and as abronchodilator. (WHO.)

Contraindicated in anxiety, restlessness, high blood pressure, glucoma, impaired circulation of the cerebrum, adenoma of prostate with residual urine accumulation, pheochromocy- toma, thyrotoxicosis. (German Commission E.)

Ephedra is official in the national pharmacopoeias of China, Japan and Germany. The herb is listed in Ayurvedic Pharmacopoeia. Only its isolated derivatives, ephedrine and ephedrine hydrochloride are official in Indian Pharmacopoeia.

Ephedrine is toxic at more than 300 mg in 1 day (Francis Brinker.)

Aerial parts yielded ephedrine and ephedroxane. Pseudoephedrine is the most active anti-inflammatory principle of Ephedra sp., it exhibited inhibitory action on a number of acute inflammations. Ephedroxane possesses a minor anti-inflammatory principle. Among the Indian species, Ephedra major, found in Lahul, contains over 2.56% alkaloids of which nearly three fourths is ephidrine. Ephedra gerardiana contains 1.22% total alkaloids and 0.68% ephedrine.

On 30 December 2003, the FDA banned ephedra products in the US.... ephedra gerardiana

Berg.

Synonym: Acca sellowiana Berg.

Family: Myrtaceae.

Habitat: Indigenous to western Paraguay, southern Brazil, Uruguay and parts of Argentina; cultivated in South India in Nilgiris and Kodaikanal hills.

English: Feijoa, Pineapple Guava, New Zealand Banana.

Action: The fruit contains iodine and vitamin C. Iodine content varies according to locality and fluctuates from year to year, usual range is 1.64-3.9 mg/kg Fruit also contains vitamin P-active polyphenols. The fruit is found beneficial only in mild cases of thyrotoxicosis.... feijoa sellowiana

The major histocompatibility complex, or human leucocyte antigen (HLA) region, consists of genetically determined antigens, situated on chromosome 6. Found in most tissues, though to a di?ering extent, the four gene loci are known as A, B, C, D, while the individual alleles at each locus are numbered 1, 2, 3, etc. The number of possible combinations is thus enormous, and the chance of two unrelated people being identical for HLA is very low.

HLA incompatibility causes the immune response, or rejection reaction, that occurs with unmatched tissue grafts. Strong associations between HLA and susceptibility to certain diseases – notably the AUTOIMMUNE DISORDERS such as rheumatoid arthritis, insulin-dependent diabetes, and thyrotoxicosis – have been described. Certain HLA antigens occur together more frequently than would be expected by chance (linkage disequilibrium), and may have a protective e?ect, conferring resistance to a disease. (See IMMUNITY.)... hla system

Elevated thyroid levels, either functional and constitutional in nature or the more profound state of thyrotoxicosis and overt disease... hyperthyroid

A compound solution of iodine and potassium iodide used in the preoperative preparation of patients with thyrotoxicosis (see THYROID GLAND, DISEASES OF). The solution is taken orally.... lugol’s solution

Compression syndrome The tense, painful state of muscles induced by excessive accumulation of INTERSTITIAL ?uid in them, following unusual exercise. This condition is more liable to occur in the muscles at the front of the shin, because they lie within a tight fascial membrane: here the syndrome is known as the anterior tibial syndrome (‘shin splints’). Prevention consists of always keeping ?t and in training for the amount of exercise to be undertaken. Equally important is what is known in sporting circles as ‘warming down’: i.e., at the end of training or a game, exercise should be gradually tailed o?. Treatment consists of elevation of the affected limb, compression of it by compression bandages, with ample exercise of the limb within the bandage, and massage. In more severe cases DIURETICS may be given. Occasionally surgical decompression may be necessary.

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

Copious PERSPIRATION occurring in bed at night and found in conditions such as TUBERCULOSIS, BRUCELLOSIS and lymphomas (see LYMPHOMA), as well as thyrotoxicosis (see under THYROID GLAND, DISEASES OF), anxiety states and menopausal ?ushes (see MENOPAUSE).... night sweats

A regular heart rate of 100 or more beats a minute, caused by increased electrical activity in the SINOATRIAL NODE (see also HEART). This level of tachycardia is normal during and just after exercise, and may also be caused by stress or anxiety. If tachycardia persists when the person is resting, it may be due to underlying disease such as thyrotoxicosis (see under THYROID GLAND, DISEASES OF) and investigation is advisable.... sinus tachycardia

(dermoid) a benign tumour – a type of *teratoma – containing developmentally mature skin complete with hair follicles and sebaceous glands, and often pockets of sebum, blood, fat, bone, nails, teeth, eyes, cartilage, and thyroid tissue, which may give rise to symptoms of thyrotoxicosis. It is usually found at sites marking the fusion of developing sections of the body in the embryo and is the most common benign ovarian tumour in girls and young women. Sometimes a dermoid cyst may develop after an injury. Treatment is complete surgical removal, preferably in one piece and without any spillage of cyst contents. Tumours in the skin are best removed by a plastic surgeon. Because of the risks of surgery and anaesthesia to pregnant women, it is usually considered more feasible to remove bilateral dermoid cysts of the ovaries discovered during pregnancy only if they grow beyond 6 cm in diameter. The procedure is usually performed through laparotomy or very carefully through laparoscopy and should preferably be done in the second trimester.... dermoid cyst

n. paralysis of the muscles of the eye. Internal ophthalmoplegia affects the muscles inside the eye: the iris (which controls the size of the pupil) and also the ciliary muscle (which is responsible for *accommodation). External ophthalmoplegia affects the muscles moving the eye. Chronic progressive external ophthalmoplegia is a progressive disease of the extrinsic eye muscles leading to *ptosis and then paralysis of the muscles; eye movements become increasingly frozen in the primary position. Ophthalmoplegia may accompany *exophthalmos due to thyrotoxicosis. Internuclear ophthalmoplegia (INO), due to a lesion in the brainstem, is seen, for example, in patients with multiple sclerosis or stroke.... ophthalmoplegia

reddening of the palms. This may be a variant of normal or a feature of pregnancy. It is also associated with chronic liver disease, connective tissue disease (such as rheumatoid arthritis), endocrine disorders (such as diabetes mellitus and thyrotoxicosis), certain infections, drugs, and smoking. There is no specific management for this condition.... palmar erythema

n. an awareness of the heartbeat. This is normal with fear, emotion, or exertion. It may also be a symptom of neurosis, arrhythmias, heart disease, and overactivity of the circulation (as in thyrotoxicosis).... palpitation

n. a drug (see beta blocker) used to treat abnormal heart rhythm, angina, and high blood pressure; it is also taken to relieve the symptoms of thyrotoxicosis and anxiety associated with palpitation or tremor and to prevent migraine headaches. Common side-effects include digestive upsets, sleep disturbances, lassitude, and coldness of extremities.... propranolol

n. a *thionamide antithyroid drug that is used to treat *thyrotoxicosis and to prepare patients for surgical removal of the thyroid gland. Side-effects may include rashes and digestive upsets.... propylthiouracil

the administration of an estimated amount of the radioactive isotope iodine-131 as a drink in order to treat an overactive thyroid gland (see thyrotoxicosis). The iodine concentrates in the thyroid and thus delivers its beta radiation locally, with little effect on other tissues. The gland will shrink and become euthyroid over the succeeding 8–12 weeks but there is a high incidence of subsequent hypothyroidism (up to 80%), which requires lifetime treatment with thyroxine. The treatment cannot be used if there is any suspicion of pregnancy, and the patient must stay away from young children and pregnant women for around 10 days after administration. Despite these drawbacks, radioactive iodine remains a popular form of treatment for any cause of hyperthyroidism.... radioactive iodine therapy

a dilated arteriole forming a red papule from which radiate prominent capillaries, so that it resembles a spider. Excessive numbers of spider naevi are a sign of liver cirrhosis, hepatitis, thyrotoxicosis, and rheumatoid arthritis; they are also a feature of normal pregnancy. See also telangiectasis.... spider naevus

a *teratoma of the ovary containing thyroid tissue that becomes overactive and causes thyrotoxicosis. It is diagnosed by radioiodine scanning showing a high uptake in the pelvis; the treatment is surgical removal of the affected ovary.... struma ovarii

a rarely seen but well-documented alteration in the shape of the nails resembling *clubbing but unique to Graves’ disease (see thyrotoxicosis). It is often associated with formation of new bone seen on X-rays of the hands and wrists, which is said to resemble bubbles along the surface of the bones.... thyroid acropachy

n. surgical removal of the thyroid gland. In partial thyroidectomy, only the diseased part of the gland is removed (e.g. one lobe); in subtotal thyroidectomy, a method of treating *thyrotoxicosis due to Graves’ disease, the surgeon removes approximately 90% of the gland.... thyroidectomy

an iodine-containing substance, synthesized and secreted by the thyroid gland, that is essential for normal metabolic processes and mental and physical development. There are two thyroid hormones, *triiodothyronine and *thyroxine, which are formed from *thyroglobulin. Lack of these hormones gives rise to *cretinism in infants and *myxoedema in adults. Excessive production of thyroid hormones gives rise to *thyrotoxicosis.... thyroid hormone

Means high BLOOD PRESSURE (raised pressure of the circulating blood), but since there is a wide range of ‘normal’ blood pressure in the population, a precise level of pressure above which an individual is deemed hypertensive is arbitrary. (A healthy young adult would be expected to have a systolic pressure of around 120 mm Hg and a diastolic of 80 mm Hg, recorded as 120/80.) Hypertension is not a disease as such but a quantitative deviation from the norm. A person with a pressure higher than the average for his or her age group is usually symptomless – although sometimes such people may develop headaches. The identi?cation of people with hypertension is important because it is a signal that they will be more likely to have a STROKE or myocardial infarct (coronary thrombosis or heart attack) than someone whose pressure is in the ‘normal’ range. Preventive steps can then be taken to lessen the likelihood of their developing these potentially life-threatening conditions.

Blood pressure is measured using two values. The systolic pressure – the greater of the two – represents the pressure when blood is pumped from the left VENTRICLE of the heart into the AORTA. The diastolic pressure is the measurement when both ventricles relax between beats. The pressures are measured in millimetres (mm) of mercury (Hg). Despite the grey area between normal and raised blood pressure, the World Health Organisation (WHO) has de?ned hypertension as a blood pressure consistently greater than 160 mm Hg (systolic) and 95 mm Hg (diastolic). Young children have readings well below these, but blood pressure rises with age and a healthy person may well live symptom free with a systolic pressure above the WHO ?gure. A useful working de?nition of hypertension is the ?gure at which the bene?ts of treating the condition outweigh the risks and costs of the treatment.

Between 10 and 20 per cent of the adult population in the UK has hypertension, with more men than women affected. Incidence is highest in the middle-aged and elderly. Because most people with hypertension are symptomless, the condition is often ?rst identi?ed during a routine medical examination, otherwise a diagnosis is usually made when complications occur. Many people’s blood pressure rises when they are anxious or after exercise, so if someone’s pressure is above normal at the ?rst testing, it should be taken again after, say, 10 minutes’ rest, by which time the reading should have settled to the person’s regular level. BP measurements should then be taken on two subsequent occasions. If the pressure is still high, the cause needs to be determined: this is done using a combination of personal and family histories (hypertension can run in families), a physical examination and investigations, including an ECG and blood tests for renal disease.

Over 90 per cent of hypertensive people have no immediately identi?able cause for their condition. They are described as having essential hypertension. In those patients with an identi?able cause, the hypertension is described as secondary. Among the causes of secondary hypertension are:

Lifestyle factors such as smoking, alcohol, stress, excessive dietary salt and obesity.

Diseases of the KIDNEYS.

Pregnancy (ECLAMPSIA).

Various ENDOCRINE disorders – for example, PHAEOCHROMOCYTOMA, CUSHING’S DISEASE, ACROMEGALY, thyrotoxicosis (see under THYROID GLAND, DISEASES OF).

COARCTATION OF THE AORTA.

Drugs – for example, oestrogen-containing oral contraceptives (see under CONTRACEPTION), ANABOLIC STEROIDS, CORTICOSTEROIDS, NON-STEROIDAL ANTIINFLAMMATORY DRUGS (NSAIDS).

Treatment People with severe hypertension may need prompt admission to hospital for urgent investigation and treatment. Those with a mild to moderate rise in blood pressure for which no cause is identi?able should be advised to change their lifestyle: smokers should stop the habit, and those with high alcohol consumption should greatly reduce or stop their drinking. Obese people should reduce their food consumption, especially of animal fats, and take more exercise. Everyone with hypertension should follow a low-salt diet and take regular exercise. Patients should also be taught how to relax, which helps to reduce blood pressure and, if they have a stressful life, working patterns should be modi?ed if possible. If these lifestyle changes do not reduce a person’s blood pressure su?ciently, drugs to achieve this will be needed. A wide range of anti-hypertensive drugs are available on prescription.

A ?rst-line treatment is one of the THIAZIDES, e?ective at a low dosage and especially useful in the elderly. Beta blockers (see BETAADRENOCEPTOR-BLOCKING DRUGS), such as oxprenolol, acebutol or atenolol, are also ?rst-line treatments. ACE inhibitors (see ANGIOTENSIN-CONVERTING ENZYME (ACE) INHIBITORS) and CALCIUM-CHANNEL BLOCKERS can be used if the ?rst-line choices are not e?ective. The drug treatment of hypertension is complex, and sometimes various drugs or combinations of drugs have to be tried to ?nd what regimen is e?ective and suits the patient. Mild to moderate hypertension can usually be treated in general practice, but patients who do not respond or have complications will normally require specialist advice. Patients on anti-hypertensive treatments require regular monitoring, and, as treatment may be necessary for several years, particular attention should be paid to identifying sideeffects. Nevertheless, e?ective treatment of hypertension does enable affected individuals to live longer and more comfortable lives than would otherwise be the case. Older people with moderately raised blood pressure are often able to live with the condition, and treatment with anti-hypertensive drugs may produce symptoms of HYPOTENSION.

In summary, hypertension is a complex disorder, with di?erent patients responding di?erently to treatment. So the condition sometimes requires careful assessment before the most e?ective therapy for a particular individual is identi?ed, and continued monitoring of patients with the disorder is advisable.

Complications Untreated hypertension may eventually result in serious complications. People with high blood pressure have blood vessels with thickened, less ?exible walls, a narrowed LUMEN and convoluted shape. Sometimes arteries become rigid. ANEURYSM may develop and widespread ATHEROMA (fat deposits) is apparent in the arterial linings. Such changes adversely affect the blood supply to body tissues and organs and so damage their functioning. Patients suffer STROKE (haemorrhage from or thrombosis in the arteries of the BRAIN) and heart attacks (coronary thrombosis

– see HEART, DISEASES OF). Those with hypertension may suffer damage to the retina of the EYE and to the OPTIC DISC. Indeed, the diagnosis of hypertension is sometimes made during a routine eye test, when the doctor or optician notices changes in the retinal arteries or optic disc. Kidney function is often affected, with patients excreting protein and excessive salt in their urine. Occasionally someone with persistent hypertension may suffer an acceleration of damage to the blood vessels – a condition described as ‘malignant’ hypertension, and one requiring urgent hospital treatment.

Hypertension is a potentially dangerous disease because it develops into a cycle of self-perpetuating damage. Faulty blood vessels lead to high blood pressure which in turn aggravates the damage in the vessels and thus in the tissues and organs they supply with blood; this further raises the affected individual’s blood pressure and the pathological cycle continues.... hypertension

The grouping of four small glands, about 5 mm in diameter, which lie to the side of and behind the THYROID GLAND. These glands regulate the metabolism of calcium and of phosphorus. If for any reason there is a de?ciency of the secretion of the parathyroid glands, the amount of calcium in the blood falls too low and the amount of phosphorus increases. The result is the condition known as TETANY characterised by restlessness and muscle spasms – sometimes severe. The condition is checked by the injection of calcium gluconate, which causes an increase in the amount of calcium in the blood.

The most common cause of this condition (hypoparathyroidism) is accidental injury to or removal of the glands during the operation of thyroidectomy for the treatment of Graves’ disease (see THYROID GLAND, DISEASES OF – Thyrotoxicosis). If there is over-production of the parathyroids, there will be an increase of calcium in the blood: this extra calcium is drawn from the bones, causing cysts to form with resulting bone fragility. This cystic disease of bone is known as OSTEITIS FIBROSA CYSTICA. Tumours of the parathyroid glands result in this overactivity of the parathyroid hormone, and the resulting increase in the amount of calcium in the blood leads to the formation of stones in the kidneys. The only available treatment is surgical removal of the tumour. Increased activity of the parathyroid glands, or hyperparathyroidism, may cause stones in the kidneys. (See KIDNEYS, DISEASES OF.)... parathyroid

A highly vascular organ situated in front of the neck. It consists of a narrow isthmus crossing the windpipe close to its upper end, and joining together two lateral lobes which run upwards, one on each side of the LARYNX. The gland is therefore shaped somewhat like a horseshoe, each lateral lobe being about 5 cm (2 inches) long and the isthmus about 12 mm (••• inch) wide, and it is ?rmly bound to the larynx. The weight of the thyroid gland is about 28·5 grams (1 ounce), but it is larger in females than in males and in some women increases in size during MENSTRUATION. It often reaches an enormous size in the condition known as GOITRE (see also THYROID GLAND, DISEASES OF).

Function The chief function of the thyroid gland is to produce a hormone (see HORMONES) rich in iodine – THYROXINE, which controls the rate of body METABOLISM. Thus, if it is de?cient in infants they fail to grow and suffer LEARNING DISABILITY, a condition formerly known as CRETINISM. If the de?ciency develops in adult life, the individual becomes obese, lethargic, and develops a coarse skin, a condition known as hypothyroidism (see under THYROID GLAND, DISEASES OF). Overactivity of the thyroid, or hyperthyroidism, results in loss of weight, rapid heart action, anxiety, overactivity and increased appetite. (See THYROID GLAND, DISEASES OF – Thyrotoxicosis.)

The production of the thyroid hormone is controlled by a hormone of the PITUITARY GLAND – the thyrotrophic hormone.... thyroid gland

Arrhythmia. Heart flutter. Disorderly uncoordinated contraction of atrial muscle wall, the ventricles responding irregularly.

Causes: thyrotoxicosis, valvular or coronary disease. Present in mitral stenosis and myocarditis. Precursor of heart failure. Carrying a bucket of coal upstairs may be sufficient to precipitate an attack. Symptoms. Pulse irregular in time and force, breathlessness, visible pulse in neck, excessive heart beats of sudden onset or permanent, with breathlessness often from emotional excitement.

Treatment. Patient should avoid excessive physical exercise or give way to anxiety and depression. Alternatives:– Tea. Equal parts: Hawthorn (berries or blossoms), Broom, Valerian. 1-2 teaspoons in each cup boiling water; infuse 5-15 minutes; dose – half-1 cup thrice daily.

Tablets/capsules. Hawthorn, Valerian, Motherwort.

Formula. Hawthorn 2; Passion flower 2; Broom 3. Mix. Dose: Powders: 750mg (three 00 capsules or half a teaspoon). Liquid extracts: 1 teaspoon. Tinctures: 2 teaspoons. In water or honey thrice daily. Practitioner. Tincture Gelsemium (BPC 1973): 2-5 drops. Tincture Lily of the Valley: 0.5-1ml.

Undue violence. Tincture Gelsemium 1; Tincture Cactus 2. Mix. Dose: 5-10 drops. Where heart muscle is damaged, add 1 part Liquid Extract Black Cohosh.

Broom. Spartiol Drops, 20 drops thrice daily. (Klein)

Diet. See: DIET – HEART AND CIRCULATION. ... atrial fibrillation

An autoimmune disorder that is characterized by toxic goitre (an overactive and enlarged thyroid gland), excessive production of thyroid hormones leading to thyrotoxicosis, and exophthalmos.... graves’ disease

A disagreeable feeling caused by the need for food. Hunger occurs when the stomach is empty and the blood glucose level is low, often following strenuous exercise. In response to these stimuli, messages from the hypothalamus cause the muscular stomach wall to contract in a rhythmic manner; these contractions, if they are pronounced, produce hunger pains.

Hunger due to a low blood sugar level can also occur in thyrotoxicosis, and in diabetes mellitus when an incorrect balance between insulin and carbohydrate intake causes hypoglycaemia.... hunger

Water horehound. Gipsywort. German: Gemeiner Wolfstrapp. French: Lycope. Italian: Licopo. Lycopus europaeus and Lycopus virginicus. Properties of both plants are the same. Dried herb. Action: “cardio-active diuretic, increasing force of myocardial contraction and reducing heart rate” BHP (1983). Palpitation, peripheral vasoconstrictor, antitussive, hypoglycaemic, sedative, anti-haemorrhagic, thyrostatic, narcotic (mild).

Mild contraceptive containing lithospermum acid which blocks gonadotropic hormones of the anterior pituitary (Rudolf F. Weiss MD)

Uses: To reduce rapid heart beat from over-active thyroid. Reduces high pulse rate in thyrotoxicosis with heart involvement. Raises blood sugar levels in diabetes. Internal haemorrhages, bleeding from the lungs, menorrhagia. High blood pressure.

Combinations. With Lily of the Valley (Bugleweed 2; Lily 1) for heart cases. With Elecampane (equal parts) for cough of tuberculosis. With Valerian 1 for thyrotoxicosis.

Preparations: Thrice daily.

Tea: 1 heaped teaspoon to each cup boiling water; infuse 10 minutes. Dose: half-1 cup. Tincture BHP (1983) 1 part to 5 parts 45 per cent alcohol. Dose: 2-6ml in water. ... bugleweed

Ephedra sinica stapf., Ephedra equisentina Bunge and Ephedra gerardiana Wall (including Ephedra nebrodensis Tineo). Twigs. German: Meertra?ubchen. French: Ephe?dre. Italian: Uva di mare. Iranian: Huma. Japanese: Ma oh. Indian: Butshur. Chinese: Ma Huang.

Constituents: Alkaloids – ephedrine, pseudoephedrine.

Action: brain, heart and circulatory stimulant, antasthmatic, bronchodilator, anti-allergic, vasodilator, hypertensive, diaphoretic. Dilates vessels of the heart causing a rise in blood pressure. Cough sedative. Febrifuge, antispasmodic. The essential oil has antibacterial and antiviral properties.

Uses: Practitioner’s first choice for asthma. Bronchitis, breathlessness, whooping cough. Used for such chest conditions for over a millennia in Chinese medicine.

Allergies: hay fever, irritative skin rashes. Low blood pressure. Hypothermia. Bed-wetting. Myasthenia gravis BHP (1983). Chinese Barefoot doctors inject the tea into nostrils for hay fever.

Usually given with expectorants: Liquorice, Lobelia, Senega, Sundew. “Combines well with Lobelia and Skunk Cabbage for bronchitis; and with Horsetail for frequency of urine.” (Fletcher Hyde) Contra-indications: hypertension, coronary thrombosis, thyrotoxicosis, glaucoma. Not given with anti- depressants (MAO inhibitors).

Preparations: Thrice daily. Average dose: 15-60mg.

Tea. Quarter to half a teaspoon herb to cup water simmered gently 5 minutes. Half a cup. Liquid extract. BHP (1983) 1:1 in 45 per cent alcohol. Dose: 15-45 drops (1-3ml). Tincture BHP (1983) 1 part to 4 parts 45 per cent alcohol. Dose: 6-8ml.

Ephedrine. Maximum dose: 30mg. Maximum daily dose 60mg.

Store in airtight container out of the light. Pharmacy only medicine. Practitioners only. ... ephedra

Failure of the right ventricle to hold its own with the return flow of blood and to re-direct it through the lungs where it is re-oxygenated before entering the left ventricle for completing the circulatory cycle. Usually secondary to failure of the left ventricle. May be caused by valvular disease, especially narrowing of the orifice of the mitral valve.

Mitral disease leads to heart failure either by a narrowing of the orifice (stenosis) or a regurgitation blocks the passage of blood from the left atrium (auricle) to the left ventricle. The left atrium enlarges (hypertrophies) in an effort to counter the impediment. Real compensation – increased thrust of the blood – is provided by the right ventricle. In order to overcome a mitral impediment the right ventricle has to enlarge.

Sooner or later the right ventricle cannot enlarge any further and general heart failure sets in. Though caused primarily by a lesion of the mitral valve, it may be secondary to left ventricular failure (LVF), thyroid disorder (thyrotoxicosis), pericarditis, congenital heart disease, or any disease which weakens ventricular muscle.

Venous congestion and back pressure of RVF leads to congestion and accumulation of fluid in the lungs, cough and spitting of blood, painful swelling of the liver, nausea, loss of appetite and severe wasting.

Where the right ventricle fails to move the blood forward as it arrives from the systemic circulation, generalised dropsy sets in. Congestion of the kidneys leads to reduced urinary excretion and presence of albumin in the urine.

The picture is well known to the cardiac practitioner: blueness of the skin, congestion of the brain circulation with sleeplessness and delirium. Soon the tension of water-logged tissues results in pain and extreme anxiety. Feet are swollen and ankles pit on pressure; chest cavities fill with fluid and the abdomen swells (ascites).

Alternatives. Cardio-tonics would be given to strengthen the ventricle and diuretics to correct fluid retention: Lily of the Valley, Hawthorn, Motherwort, Broom. BHP (1983).

Due to rheumatic fever: Hawthorn.

High Blood Pressure: Mistletoe.

Effort Syndrome: Motherwort.

Tinctures. Combine, Lily of the Valley 2; Hawthorn 2; Motherwort 3. Dose: 1 teaspoon thrice daily after meals.

Diet. Low salt, low fat, high fibre. Restricted fluids, vegetarian protein foods, yoghurt. See also: DIET – HEART AND CIRCULATION.

Supplements. Potassium (bananas), Vitamin B6.

General. Stop smoking. Correction of overweight. Complete bed-rest with legs raised above level of the abdomen and patient propped-up to relieve difficult breathing. ... heart – right ventricular failure (rvf)

A momentary delay in the normal downward movement of the upper eyelids that occurs when the eye looks down.

Lid lag is a characteristic feature of thyrotoxicosis, and usually occurs in conjunction with exophthalmos.... lid lag

a condition seen in older patients with *thyrotoxicosis, characterized by weight loss, slow atrial fibrillation, and severe depressive illness, rather than the usual florid symptoms. They have small goitres on examination and the blood tests confirm thyrotoxicosis, which is treated in the standard manner.... apathetic hyperthyroidism

n. a *thionamide used to reduce the production of thyroid hormone in cases of overactivity of the gland (thyrotoxicosis). A prodrug, it is converted to its biologically active metabolite, methimazole, within the body. Gastrointestinal upsets, rashes, and itching may occur; more rarely, carbimazole may cause *myelosuppression.... carbimazole

A group of drugs, also known as beta-adrenergic blocking agents, prescribed principally to treat heart and circulatory disorders such as angina and hypertension. Beta-blockers block the effects of the sympathetic nervous system, which releases adrenaline (epinephrine) and noradrenaline (norepinephrine) at nerve endings that are known as beta receptors.

There are 2 types of beta receptor: beta 1 and beta 2. Beta 1 receptors are present in the heart and blood vessels, and beta 2 in the lungs. Some betablockers (such as acebutolol, atenolol, and metoprolol) are termed cardioselective and, because they act mostly on beta 1 receptors, are used mainly to treat heart disease such as angina, hypertension, and cardiac arrhythmia. The drugs are sometimes given after a myocardial infarction (heart attack) to reduce the likelihood of further damage to the heart muscle.

Other types of beta-blocker, such as oxprenolol, propranolol, and timolol, may be given to prevent migraine attacks by acting on blood vessels in the head; reduce the physical symptoms of anxiety; or control the symptoms of thyrotoxicosis. Beta-blocker drugs such as timolol are sometimes given in the

form of eye drops to treat glaucoma and work by lowering the fluid pressure in the eyeball.

Beta-blockers may reduce an individual’s capacity for strenuous exercise. The drugs may worsen the symptoms of asthma, bronchitis, or other forms of lung disease. They may also reduce the flow of blood to the limbs, causing cold hands and feet. In addition, sleep disturbance and depression can be side effects of beta-blockers.... beta-blocker drugs

Elevation above normal of body temperature. Normal body temperature is 37oC in the mouth and 0.6oC lower in the axilla (armpit). A fever may be accompanied by symptoms such as shivering, headache, sweating, thirst, faster-thannormal breathing, and a flushed face. Confusion or delirium sometimes occur, especially in the elderly; a high fever may cause seizures in a child under 5 years (see convulsion, febrile) or coma.

Most fevers are caused by a bacterial infection such as tonsillitis or a viral infection such as influenza. In these cases, proteins called pyrogens are released when the white blood cells fight the microorganisms that are responsible for the infection. Pyrogens act on the temperature controlling centre in the brain, causing it to raise the body temperature in an attempt to destroy the invading microorganisms. Fever may also occur in conditions, such as dehydration, thyrotoxicosis, lymphoma, and myocardial infarction, where infection is not present.

Drugs such as aspirin or other nonsteroidal anti-inflammatory drugs, or paracetamol may be given to reduce fevers that are due to infections.

Otherwise, treatment is directed at the underlying cause (for example, giving antibiotic drugs for a bacterial infection).... fever

An element essential for formation of the thyroid hormones, triiodothyronine (T3) and thyroxine (T4), which control the rate of metabolism (internal chemistry) and growth and development. Dietary shortage may lead to goitre or hypothyroidism. Deficiency in the newborn can, if left untreated, lead to cretinism. Shortages are very rare in developed countries due to bread and table salt being fortified with iodide or iodate. Radioactive iodine is sometimes used to reduce thyroid gland activity in cases of thyrotoxicosis and in the treatment of thyroid cancer. Iodine compounds are used as antiseptics, in radiopaque contrast media in some X-ray procedures (see imaging techniques), and in some cough remedies.... iodine

Treatment of cancer and, occasionally, some noncancerous tumours, by X-rays or other radiation. Radioactive sources produce ionizing radiation, which destroys or slows down the development of abnormal cells. Normal cells suffer little or no longterm damage, but short-term damage is a side effect.Radiotherapy may be used on its own in an attempt to destroy all the abnormal cells in various types of cancer, such as squamous cell carcinoma and Hodgkin’s disease. It may also be used with other cancer treatments. Surgical excision of a cancerous tumour is often followed by radiotherapy to destroy any remaining tumour cells. Radiotherapy may also be used to relieve the symptoms of a cancer that is too advanced to be cured.

If benefits outweigh risks, radiotherapy may be used to treat noncancerous diseases; for example, part of an overactive thyroid gland (see thyrotoxicosis) may be destroyed using radioactive iodine.

Radiotherapy is usually performed on an outpatient basis. X-rays (or sometimes electrons) produced by a machine called a linear accelerator are aimed at the tumour from many directions. This produces a large enough dose of radiation to destroy the tumour. Alternatively, a source of radiation, in the form of tiny pellets, is inserted into the tumour through a hollow needle (see interstitial radiotherapy) or into a body cavity (see intracavitary therapy). Radioactive iodine used to treat thyrotoxicosis is given in liquid form and drunk through a straw.

There may be unpleasant side effects, including fatigue, nausea and vomiting, and loss of hair from irradiated areas. Rarely, there may be reddening and blistering of the skin.... radiotherapy

(Graves’ disease) see thyrotoxicosis.... exophthalmic goitre

(proptometer) n. an instrument for measuring the distance from the edges of the bony orbits to the corneas to ascertain the degree of *exophthalmos in Graves’ disease (see thyrotoxicosis).... exophthalmometer

(exophthalmic goitre) see thyrotoxicosis. [R. J. Graves (1797–1853), Irish physician]... graves’ disease

n. overactivity of the thyroid gland, either due to a tumour, overgrowth of the gland, or *Graves’ disease. See thyrotoxicosis.... hyperthyroidism

(aqueous iodine oral solution) a solution of 5% iodine and 10% potassium iodide, used in the treatment of thyrotoxicosis in emergencies, such as *thyroid crisis, or when surgery cannot wait for more conventional treatments. For its mode of action it utilizes the abnormal *Wolff–Chaikoff effect, seen in cases of thyroiditis. [J. G. A. Lugol (1786–1851), French physician]... lugol’s solution

(thyroid storm) a life-threatening condition due to an acute and severe exacerbation of previously undiagnosed or inadequately treated *thyrotoxicosis. It often follows infections, childbirth, nonthyroid surgery, or trauma but can occur without an obvious cause. The presenting features are a fever, severe agitation, nausea and vomiting, diarrhoea, and abdominal pains. An accelerated heart rate and irregularity of the heart rhythm can cause heart failure, and psychotic episodes or coma can result. Blood tests will reveal hyperthyroidism and may also show altered liver function, high blood sugar, high calcium levels, a high white blood cell count, and often anaemia. Treatment is with intravenous fluids, oxygen, antithyroid drugs (such as *carbimazole or *propylthiouracil), high-dose iodide solution (see Lugol’s solution), high-dose steroids, and beta blockers. The patient must be cooled and given antipyretics, such as paracetamol. Any underlying cause must also be treated.... thyroid crisis

a condition in which attacks of sudden weakness and flaccidity occur in patients with *thyrotoxicosis, seen most often in males of Asian descent. The attacks last from hours to days; they can be prevented by potassium supplements and subsequent treatment of the thyrotoxicosis.... thyrotoxic periodic paralysis