Hypothyroidism Health Dictionary

An out-of-date name for congenital HYPOTHYROIDISM, a disease caused by defective thyroid function in fetal life or early in infancy.... cretinism

See under THYROID GLAND, DISEASES OF – Hypothyroidism.... myxoedema

Absence of MENSTRUATION at the time of life at which it should normally occur. If menstruation has never occurred, the amenorrhoea is termed primary; secondary amenorrhoea is de?ned as menstruation ceasing after a normal cycle has been experienced for a number of years.

A few patients with primary amenorrhoea have an abnormality of their CHROMOSOMES or malformation of the genital tract such as absecence of the UTERUS (see TURNER’S SYNDROME). A gynaecological examination will rarely disclose an IMPERFORATE HYMEN in a young girl who may also complain of regular cycles of pain like period pains.

There are many causes of secondary amenorrhoea and management requires dealing with the primary cause. The commonest cause is pregnancy. Disorders of the HYPOTHALAMUS and related psychological factors such as anorexia nervosa (see EATING DISORDERS) also cause amenorrhoea, as can poor nutrition and loss of weight by extreme dieting. It is common in ballet dancers and athletes who exercise a great deal, but can also be triggered by serious illnesses such as tuberculosis or malaria. Excess secretion of prolactin, either due to a micro-adenoma (see ADENOMA) of the PITUITARY GLAND or to various prescription drugs will produce amenorrhoea, and sometimes GALACTORRHOEA as well. Malfunction of other parts of the pituitary gland will cause failure to produce GONADOTROPHINS, thus causing ovarian failure with consequent amenorrhea. In CUSHING’S SYNDROME, amenorrhoea is caused by excessive production of cortisol. Similarly, androgen-production abnormalities are found in the common POLYCYSTIC OVARY SYNDROME. These conditions also have abnormalities of the insulin/glucose control mechanisms. Taking the contraceptive pill is not now considered to provoke secondary amenorrhoea but OBESITY and HYPOTHYROIDISM are potential causes.

When the cause is weight loss, restoring body weight may alone restore menstruation. Otherwise, measuring gonadotrophic hormone levels will help show whether amenorrhoea is due to primary ovarian failure or secondary to pituitary disease. Women with raised concentrations of serum gonadotrophic hormones have primary ovarian failure. When amenorrhoea is due to limited pituitary failure, treatment with CLOMIPHENE may solve the problem.... amenorrhoea

The term used to describe a person whose thyroid gland is functioning normally, especially someone who has been successfully treated for either hypothyroidism or hyperthyroidism.... euthyroid

Depression is a word that is regularly misused. Most people experience days or weeks when they feel low and fed up (feelings that may recur), but generally they get over it without needing to seek medical help. This is not clinical depression, best de?ned as a collection of psychological symptoms including sadness; unhappy thoughts characterised by worry, poor self-image, self-blame, guilt and low self-con?dence; downbeat views on the future; and a feeling of hopelessness. Su?erers may consider suicide, and in severe depression may soon develop HALLUCINATIONS and DELUSIONS.

Doctors make the diagnosis of depression when they believe a patient to be ill with the latter condition, which may affect physical health and in some instances be life-threatening. This form of depression is common, with up to 15 per cent of the population suffering from it at any one time, while about 20 per cent of adults have ‘medical’ depression at some time during their lives – such that it is one of the most commonly presenting disorders in general practice. Women seem more liable to develop depression than men, with one in six of the former and one in nine of the latter seeking medical help.

Manic depression is a serious form of the disorder that recurs throughout life and is manifested by bouts of abnormal elation – the manic stage. Both the manic and depressive phases are commonly accompanied by psychotic symptoms such as delusions, hallucinations and a loss of sense of reality. This combination is sometimes termed a manic-depressive psychosis or bipolar affective disorder because of the illness’s division into two parts. Another psychiatric description is the catch-all term ‘affective disorder’.

Symptoms These vary with the illness’s severity. Anxiety and variable moods are the main symptoms in mild depression. The sufferer may cry without any reason or be unresponsive to relatives and friends. In its more severe form, depression presents with a loss of appetite, sleeping problems, lack of interest in and enjoyment of social activities, tiredness for no obvious reason, an indi?erence to sexual activity and a lack of concentration. The individual’s physical and mental activities slow down and he or she may contemplate suicide. Symptoms may vary during the 24 hours, being less troublesome during the latter part of the day and worse at night. Some people get depressed during the winter months, probably a consequence of the long hours of darkness: this disorder – SEASONAL AFFECTIVE DISORDER SYNDROME, or SADS – is thought to be more common in populations living in areas with long winters and limited daylight. Untreated, a person with depressive symptoms may steadily worsen, even withdrawing to bed for much of the time, and allowing his or her personal appearance, hygiene and environment to deteriorate. Children and adolescents may also suffer from depression and the disorder is not always recognised.

Causes A real depressive illness rarely has a single obvious cause, although sometimes the death of a close relative, loss of employment or a broken personal relationship may trigger a bout. Depression probably has a genetic background; for instance, manic depression seems to run in some families. Viral infections sometimes cause depression, and hormonal disorders – for example, HYPOTHYROIDISM or postnatal hormonal disturbances (postnatal depression) – will cause it. Di?cult family or social relations can contribute to the development of the disorder. Depression is believed to occur because of chemical changes in the transmission of signals in the nervous system, with a reduction in the neurochemicals that facilitate the passage of messages throughout the system.

Treatment This depends on the type and severity of the depression. These are three main forms. PSYCHOTHERAPY either on a one-to-one basis or as part of a group: this is valuable for those whose depression is the result of lifestyle or personality problems. Various types of psychotherapy are available. DRUG TREATMENT is the most common method and is particularly helpful for those with physical symptoms. ANTIDEPRESSANT DRUGS are divided into three main groups: TRICYCLIC ANTIDEPRESSANT DRUGS (amitriptyline, imipramine and dothiepin are examples); MONOAMINE OXIDASE INHIBITORS (MAOIS) (phenelzine, isocarboxazid and tranylcypromine are examples); and SELECTIVE SEROTONIN REUPTAKE INHIBITORS (SSRIS) (?uoxetine – well known as Prozac®, ?uvoxamine and paroxetine are examples). For manic depression, lithium carbonate is the main preventive drug and it is also used for persistent depression that fails to respond to other treatments. Long-term lithium treatment reduces the likelihood of relapse in about 80 per cent of manic depressives, but the margin between control and toxic side-effects is narrow, so the drug must be carefully supervised. Indeed, all drug treatment for depression needs regular monitoring as the substances have powerful chemical properties with consequential side-effects in some people. Furthermore, the nature of the illness means that some sufferers forget or do not want to take the medication. ELECTROCONVULSIVE THERAPY (ECT) If drug treatments fail, severely depressed patients may be considered for ECT. This treatment has been used for many years but is now only rarely recommended. Given under general anaesthetic, in appropriate circumstances, ECT is safe and e?ective and may even be life-saving, though temporary impairment of memory may occur. Because the treatment was often misused in the past, it still carries a reputation that worries patients and relatives; hence careful assessment and counselling are essential before use is recommended.

Some patients with depression – particularly those with manic depression or who are a danger to themselves or to the public, or who are suicidal – may need admission to hospital, or in severe cases to a secure unit, in order to initiate treatment. But as far as possible patients are treated in the community (see MENTAL ILLNESS).... depression

A collection of disorders in which some part of the body’s internal chemistry (see METABOLISM; CATABOLISM) is disrupted. Some of these disorders arise from inherited de?ciencies in which a speci?c ENZYME is absent or abnormal, or does not function properly. Other metabolic disorders occur because of malfunctions in the endocrine system (see ENDOCRINE GLANDS). There may be over- or underproduction of a hormone involved in the control of metabolic activities: a prime example is DIABETES MELLITUS – a disorder of sugar metabolism; others include CUSHING’S SYNDROME; hypothyroidism and hyperthyroidism (see THYROID GLAND, DISEASES OF); and insulinoma (an insulin-producing tumour of the pancreas). The bones can be affected by metabolic disorders such as osteoporosis, osteomalacia (rickets) and Paget’s disease (see under BONE, DISORDERS OF). PORPHYRIAS, HYPERLIPIDAEMIA, HYPERCALCAEMIA and gout are other examples of disordered metabolism.

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

Slow heart rate; less than 55 beats per minute. Cause may be disease of the heart muscle or may lie in the CNS (central nervous system). May also be caused by disorder of the thyroid gland (hypothyroidism) with dropsy-like swelling of face and hands. Of recent years bradycardia has been associated with beta-blocker drugs, reserpine and digitalis alkaloids given in excess. Wrist pulse is slow. In the aged it is present as weakness and worsened by hypothermia.

In total heart block a rate of 36 or less is due to failure of conduction from atria to ventricles: requires artificial pace maker.

Modern herbalism (phytotherapy) employs: Hawthorn berries, Prickly Ash bark (berries preferred for circulatory disorders), Lily of the Valley leaves, Bugleweed (Lycopus virginicus), Broom, Heart’s Ease, Holy Thistle, Cactus (Night blooming cereus), Nutmeg, Saffron, Lemon Balm, Thuja, Figwort, Ginseng.

Lily of the Valley has a specific action in the heart muscle.

One of the purest and positive stimulants known for increasing the pulse rate is Cayenne Pepper. A few grains sprinkled on a meal or added to a beverage coaxes the heart to increase its output. To give the heart just that little extra support it may need, gentle cardiac stimulants can be found in the kitchen: Cloves, Ginger, Horseradish, Peppermint, Red Sage, Garden Sage.

Where a slow beat arises from a serious heart condition the underlying disorder should receive priority. In the event of an emergency the restorative, Camphor, may be given until the doctor comes:– 1-5 drops oil of Camphor in a teaspoon of honey. Even inhalation of the oil is known to increase pulse rate.

A slow pulse can be increased in pace by vagal relaxation. The pulse may be slow because of an excess of bile salts in the blood when a liver remedy (say Dandelion) would be indicated. Slow pulse of convalescence (Gentian), diabetes (Goat’s Rue), glandular fever (Poke root), jaundice (Dandelion), low thyroid (Kelp), congestion in the brain (Cypripedium), nervous exhaustion (Ginseng).

Practitioner. Broom (Spartiol Drops), 20 drops thrice daily. (Klein) Diet and supplements. See: DIET – HEART AND CIRCULATION. ... bradycardia

Alopecia means hair loss. It may be localised or total in the scalp. The commonest type, which is hereditary, is male baldness (androgenic alopecia). Female balding spares the anterior hair line, develops later, and is less severe than the male variety. Di?use hair loss is common after childbirth, severe illness or infection (telogen alopecia); it begins 8–12 weeks after the causative event and recovery is complete. Persistent di?use hair loss may be caused by severe iron de?ciency or HYPOTHYROIDISM, or may be drug-induced.

Patchy localised hair loss is commonly caused by fungal infections (tinea capitis – see RINGWORM), especially in the tropics. It may also be due to trauma, such as hair-pulling by children or disturbed adults, or hair-straightening by African or Afro-Caribbean women (traction alopecia). Rarely, diseases of the scalp-skin such as discoid lupus erythematosus (see under LUPUS) or lichen planus (see under LICHEN) may cause patchy alopecia with scarring which is irreversible. The long-term effects of radiotherapy may be similar.

Treatment depends on the cause. Speci?c antifungal drugs cure tinea capitis. Correction of thyroid or iron de?ciency may be dramatic. Male baldness may be modi?ed slightly by long-term use of minoxidil lotion, or improved permanently by various types of hair-follicle grafting of transplants from the occipital scalp. Female balding may be amenable to anti-androgen/oestrogen regimens, but severe forms require a wig.... alopecia

A condition in which a person infrequently passes hard FAECES (stools). Patients sometimes complain of straining, a feeling of incomplete evacuation of faeces, and abdominal or perianal discomfort. A healthy individual usually opens his or her bowels once daily but the frequency may vary, perhaps twice daily or once only every two or three days. Constipation is generally de?ned as fewer than three bowel openings a week. Healthy people may have occasional bouts of constipation, usually re?ecting a temporary change in diet or the result of taking drugs – for example, CODEINE – or any serious condition resulting in immobility, especially in elderly people.

Constipation is a chronic condition and must be distinguished from the potentially serious disorder, acute obstruction, which may have several causes (see under INTESTINE, DISEASES OF). There are several possible causes of constipation; those due to gastrointestinal disorders include:

Dietary: lack of ?bre; low ?uid consumption.

Structural: benign strictures (narrowing of gut); carcinoma of the COLON; DIVERTICULAR DISEASE.

Motility: poor bowel training when young; slow transit due to reduced muscle activity in the colon, occurring usually in women; IRRITABLE BOWEL SYNDROME (IBS); HIRSCHSPRUNG’S DISEASE.

•Defaecation: anorectal disease such as ?ssures, HAEMORRHOIDS and CROHN’S DISEASE; impaction of faeces. Non-gastrointestinal disorders causing constipation include:

Drugs: opiates (preparations of OPIUM), iron supplements, ANTACIDS containing aluminium, ANTICHOLINERGIC drugs.

Metabolic and endocrine: DIABETES MELLITUS, pregnancy (see PREGNANCY AND LABOUR), hypothyroidism (see under THYROID GLAND, DISEASES OF).

Neurological: cerebrovascular accidents (STROKE), MULTIPLE SCLEROSIS (MS), PARKINSONISM, lesions in the SPINAL CORD. Persistent constipation for which there is no

obvious cause merits thorough investigation, and people who experience a change in bowel habits – for example, alternating constipation and diarrhoea – should also seek expert advice.

Treatment Most people with constipation will respond to a dietary supplement of ?bre, coupled, when appropriate, with an increase in ?uid intake. If this fails to work, judicious use of LAXATIVES for, say, a month is justi?ed. Should constipation persist, investigations on the advice of a general practitioner will probably be needed; any further treatment will depend on the outcome of the investigations in which a specialist will usually be involved. Successful treatment of the cause should then return the patient’s bowel habits to normal.... constipation

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

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

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

Paediatrics is the branch of medicine which deals with diseases of children, but many paediatricians have a wider role, being employed largely outside acute hospitals and dealing with child health in general.

History Child health services were originally designed, before the NHS came into being, to ?nd or prevent physical illness by regular inspections. In the UK these were carried out by clinical medical o?cers (CMOs) working in infant welfare clinics (later, child health clinics) set up to ?ll the gap between general practice and hospital care. The services expanded greatly from the mid 1970s; ‘inspections’ have evolved into a regular screening and surveillance system by general practitioners and health visitors, while CMOs have mostly been replaced by consultant paediatricians in community child health (CPCCH).

Screening Screening begins at birth, when every baby is examined for congenital conditions such as dislocated hips, heart malformations, cataract and undescended testicles. Blood is taken to ?nd those babies with potentially brain-damaging conditions such as HYPOTHYROIDISM and PHENYLKETONURIA. Some NHS trusts screen for the life-threatening disease CYSTIC FIBROSIS, although in future it is more likely that ?nding this disease will be part of prenatal screening, along with DOWN’S (DOWN) SYNDROME and SPINA BIFIDA. A programme to detect hearing impairment in newborn babies has been piloted from 2001 in selected districts to ?nd out whether it would be a useful addition to the national screening programme. Children from ethnic groups at risk of inherited abnormalities of HAEMOGLOBIN (sickle cell disease; thalassaemia – see under ANAEMIA) have blood tested at some time between birth and six months of age.

Illness prevention At two months, GPs screen babies again for these abnormalities and start the process of primary IMMUNISATION. The routine immunisation programme has been dramatically successful in preventing illness, handicap and deaths: as such it is the cornerstone of the public health aspect of child health, with more potential vaccines being made available every year. Currently, infants are immunised against pertussis (see WHOOPING COUGH), DIPHTHERIA, TETANUS, POLIOMYELITIS, haemophilus (a cause of MENINGITIS, SEPTICAEMIA, ARTHRITIS and epiglottitis) and meningococcus C (SEPTICAEMIA and meningitis – see NEISSERIACEAE) at two, three and four months. Selected children from high-risk groups are o?ered BCG VACCINE against tuberculosis and hepatitis vaccine. At about 13 months all are o?ered MMR VACCINE (measles, mumps and rubella) and there are pre-school entry ‘boosters’ of diphtheria, tetanus, polio, meningococcus C and MMR. Pneumococcal vaccine is available for particular cases but is not yet part of the routine schedule.

Health promotion and education Throughout the UK, parents are given their child’s personal health record to keep with them. It contains advice on health promotion, including immunisation, developmental milestones (when did he or she ?rst smile, sit up, walk and so on), and graphs – called centile charts – on which to record height, weight and head circumference. There is space for midwives, doctors, practice nurses, health visitors and parents to make notes about the child.

Throughout at least the ?rst year of life, both parents and health-care providers set great store by regular weighing, designed to pick up children who are ‘failing to thrive’. Measuring length is not quite so easy, but height measurements are recommended from about two or three years of age in order to detect children with disorders such as growth-hormone de?ciency, malabsorption (e.g. COELIAC DISEASE) and psychosocial dwar?sm (see below).

All babies have their head circumference measured at birth, and again at the eight-week check. A too rapidly growing head implies that the infant might have HYDROCEPHALUS – excess ?uid in the hollow spaces within the brain. A too slowly growing head may mean failure of brain growth, which may go hand in hand with physically or intellectually delayed development.

At about eight months, babies receive a surveillance examination, usually by a health visitor. Parents are asked if they have any concerns about their child’s hearing, vision or physical ability. The examiner conducts a screening test for hearing impairment – the so-called distraction test; he or she stands behind the infant, who is on the mother’s lap, and activates a standardised sound at a set distance from each ear, noting whether or not the child turns his or her head or eyes towards the sound. If the child shows no reaction, the test is repeated a few weeks later; if still negative then referral is made to an audiologist for more formal testing.

The doctor or health visitor will also go through the child’s developmental progress (see above) noting any signi?cant deviation from normal which merits more detailed examination. Doctors are also recommended to examine infants developmentally at some time between 18 and 24 months. At this time they will be looking particularly for late walking or failure to develop appropriate language skills.... child health

Underactivity of the PITUITARY GLAND. It can cause dwar?sm, delayed puberty, impotence, infertility, AMENORRHOEA, hypothyroidism (see THYROID GLAND, DISEASES OF), and hypoadrenalism. Causes include tumours, irradiation of the gland, SARCOIDOSIS, and necrosis associated with post-partum haemorrhage (Sheehan’s syndrome).... hypopituitarism

A preparation based on the thyroid (see THYROID GLAND) hormone triiodothyronine, which is prescribed to replace the lack of natural thyroid hormone (hypothyroidism). The drug is also used to treat goitre and cancer of the

thyroid gland. (See THYROID GLAND, DISEASES OF.)... liothyronine acid

This condition is particularly associated with PERNICIOUS ANAEMIA but can also be caused by a number of other things, such as alcohol, pregnancy, myxoedema (see THYROID GLAND, DISEASES OF – Hypothyroidism) and MYELOMATOSIS, and also by vitamin B12 de?ciency: this occurs sometimes in vegans (see VEGANISM) as well as in patients with CROHN’S DISEASE.... macrocytosis

A periodic change occurring in (female) human beings and the higher apes, consisting chie?y in a ?ow of blood from the cavity of the womb (UTERUS) and associated with various slight constitutional disturbances. It begins between the ages of 12 and 15, as a rule – although its onset may be delayed until as late as 20, or it may begin as early as ten or 11. Along with its ?rst appearance, the body develops the secondary sex characteristics: for example, enlargement of the BREASTS, and characteristic hair distribution. The duration of each menstrual period varies in di?erent persons from 2– 8 days. It recurs in the great majority of cases with regularity, most commonly at intervals of 28 or 30 days, less often with intervals of 21 or 27 days, and ceasing only during pregnancy and lactation, until the age of 45 or 50 arrives, when it stops altogether – as a rule ceasing early if it has begun early, and vice versa. The ?nal stoppage is known as the MENOPAUSE or the CLIMACTERIC.

Menstruation depends upon a functioning ovary (see OVARIES) and this upon a healthy PITUITARY GLAND. The regular rhythm may depend upon a centre in the HYPOTHALAMUS, which is in close connection with the pituitary. After menstruation, the denuded uterine ENDOMETRIUM is regenerated under the in?uence of the follicular hormone, oestradiol. The epithelium of the endometrium proliferates, and about a fortnight after the beginning of menstruation great development of the endometrial glands takes place under the in?uence of progesterone, the hormone secreted by the CORPUS LUTEUM. These changes are made for the reception of the fertilised OVUM. In the absence of fertilisation the uterine endometrium breaks down in the subsequent menstrual discharge.

Disorders of menstruation In most healthy women, menstruation proceeds regularly for 30 years or more, with the exceptions connected with childbirth. In many women, however, menstruation may be absent, excessive or painful. The term amenorrhoea is applied to the condition of absent menstruation; the terms menorrhagia and metrorrhagia describe excessive menstrual loss – the former if the excess occurs at the regular periods, and the latter if it is irregular. Dysmenorrhoea is the name given to painful menstruation. AMENORRHOEA If menstruation has never occurred, the amenorrhoea is termed primary; if it ceases after having once become established it is known as secondary amenorrhoea. The only value of these terms is that some patients with either chromosomal abnormalities (see CHROMOSOMES) or malformations of the genital tract fall into the primary category. Otherwise, the age of onset of symptoms is more important.

The causes of amenorrhoea are numerous and treatment requires dealing with the primary cause. The commonest cause is pregnancy; psychological stress or eating disorders can cause amenorrhoea, as can poor nutrition or loss of weight by dieting, and any serious underlying disease such as TUBERCULOSIS or MALARIA. The excess secretion of PROLACTIN, whether this is the result of a micro-adenoma of the pituitary gland or whether it is drug induced, will cause amenorrhoea and possibly GALACTORRHOEA as well. Malfunction of the pituitary gland will result in a failure to produce the gonadotrophic hormones (see GONADOTROPHINS) with consequent amenorrhoea. Excessive production of cortisol, as in CUSHING’S SYNDROME, or of androgens (see ANDROGEN) – as in the adreno-genital syndrome or the polycystic ovary syndrome – will result in amenorrhoea. Amenorrhoea occasionally follows use of the oral contraceptive pill and may be associated with both hypothyroidism (see under THYROID GLAND, DISEASES OF) and OBESITY.

Patients should be reassured that amenorrhoea can often be successfully treated and does not necessarily affect their ability to have normal sexual relations and to conceive. When weight loss is the cause of amenorrhoea, restoration of body weight alone can result in spontaneous menstruation (see also EATING DISORDERS – Anorexia nervosa). Patients with raised concentration of serum gonadotrophin hormones have primary ovarian failure, and this is not amenable to treatment. Cyclical oestrogen/progestogen therapy will usually establish withdrawal bleeding. If the amenorrhoea is due to mild pituitary failure, menstruation may return after treatment with clomiphene, a nonsteroidal agent which competes for oestrogen receptors in the hypothalamus. The patients who are most likely to respond to clomiphene are those who have some evidence of endogenous oestrogen and gonadotrophin production. IRREGULAR MENSTRUATION This is a change from the normal monthly cycle of menstruation, the duration of bleeding or the amount of blood lost (see menorrhagia, below). Such changes may be the result of an upset in the balance of oestrogen and progesterone hormones which between them control the cycle. Cycles may be irregular after the MENARCHE and before the menopause. Unsuspected pregnancy may manifest itself as an ‘irregularity’, as can an early miscarriage (see ABORTION). Disorders of the uterus, ovaries or organs in the pelvic cavity can also cause irregular menstruation. Women with the condition should seek medical advice. MENORRHAGIA Abnormal bleeding from the uterus during menstruation. A woman loses on average about 60 ml of blood during her period; in menorrhagia this can rise to 100 ml. Some women have this problem occasionally, some quite frequently and others never. One cause is an imbalance of progesterone and oestrogen hormones which between them control menstruation: the result is an abnormal increase in the lining (endometrium) of the uterus, which increases the amount of ‘bleeding’ tissue. Other causes include ?broids, polyps, pelvic infection or an intrauterine contraceptive device (IUD – see under CONTRACEPTION). Sometimes no physical reason for menorrhagia can be identi?ed.

Treatment of the disorder will depend on how severe the loss of blood is (some women will become anaemic – see ANAEMIA – and require iron-replacement therapy); the woman’s age; the cause of heavy bleeding; and whether or not she wants children. An increase in menstrual bleeding may occur in the months before the menopause, in which case time may produce a cure. Medical or surgical treatments are available. Non-steroidal anti-in?ammatory drugs may help, as may tranexamic acid, which prevents the breakdown of blood clots in the circulation (FIBRINOLYSIS): this drug can be helpful if an IUD is causing bleeding. Hormones such as dydrogesterone (by mouth) may cure the condition, as may an IUD that releases small quantities of a PROGESTOGEN into the lining of the womb.

Traditionally, surgical intervention was either dilatation and curettage of the womb lining (D & C) or removal of the whole uterus (HYSTERECTOMY). Most surgery is now done using minimally invasive techniques. These do not require the abdomen to be cut open, as an ENDOSCOPE is passed via the vagina into the uterus. Using DIATHERMY or a laser, the surgeon then removes the whole lining of the womb. DYSMENORRHOEA This varies from discomfort to serious pain, and sometimes includes vomiting and general malaise. Anaemia is sometimes a cause of painful menstruation as well as of stoppage of this function.

In?ammation of the uterus, ovaries or FALLOPIAN TUBES is a common cause of dysmenorrhoea which comes on for the ?rst time late in life, especially when the trouble follows the birth of a child. In this case the pain exists more or less at all times, but is aggravated at the periods. Treatment with analgesics and remedying the underlying cause is called for.

Many cases of dysmenorrhoea appear with the beginning of menstrual life, and accompany every period. It has been estimated that 5–10 per cent of girls in their late teens or early 20s are severely incapacitated by dysmenorrhoea for several hours each month. Various causes have been suggested for the pain, one being an excessive production of PROSTAGLANDINS. There may be a psychological factor in some sufferers and, whether this is the result of inadequate sex instruction, fear, family, school or work problems, it is important to o?er advice and support, which in itself may resolve the dysmenorrhoea. Symptomatic relief is of value.... menstruation

(T4) A crystalline substance, containing IODINE, isolated from the THYROID GLAND and possessing the properties of thyroid extract. It has also been synthesised. It is used in patients with defective function of the thyroid, such as myxoedema (see THYROID GLAND, DISEASES OF

– Hypothyroidism).... thyroxine

(T3) The substance which exerts the physiological action of thyroid hormone (see THYROID GLAND). It is formed in the body cells by the de-iodination of THYROXINE (tetraiodothyronine) which is the active principle secreted by the thyroid gland. It has also been synthesised, and is now available for the treatment of hypothyroidism (see THYROID GLAND, DISEASES OF). It is three times as potent as thyroxine.... tri-iodothyronine

A LIPID that is an important constituent of body cells and so widely distributed throughout the body. It is especially abundant in the brain, nervous tissue, adrenal glands and skin. It is also found in egg yolk and gall-stones (see GALLBLADDER, DISEASES OF). Cholesterol plays an important role in the body, being essential for the production of the sex hormones as well as for the repair of membranes. It is also the source from which BILE acids are manufactured. The total amount in the body of a man weighing 70 kilograms (10 stones) is around 140 grams, and the amount present in the blood is 3·6–7·8 mmol per litre or 150–250 milligrams per 100 millilitres.

A high blood-cholesterol level – that is, one over 6 mmol per litre or 238 mg per 100 ml – is undesirable as there appears to be a correlation between a high blood cholesterol and ATHEROMA, the form of arterial degenerative disease associated with coronary thrombosis and high blood pressure. This is well exempli?ed in DIABETES MELLITUS and HYPOTHYROIDISM, two diseases in which there is a high blood cholesterol, sometimes going as high as 20 mmol per litre; patients with these diseases are known to be particularly prone to arterial disease. There is also a familial disease known as hypercholesterolaemia, in which members of affected families have a blood cholesterol of around 18 mmol per litre or more, and are particularly liable to premature degenerative disease of the arteries. Many experts believe that there is no ‘safe level’ and that everybody should attempt to keep their cholesterol level as low as possible.

Cholesterol exists in three forms in the blood: high-density lipoproteins (HDLs) which are believed to protect against arterial disease, and a low-density version (LDLs) and very low-density type (VLDLs), these latter two being risk factors.

The rising incidence of arterial disease in western countries in recent years has drawn attention to this relationship between high levels of cholesterol in the blood and arterial disease. The available evidence indicates that there is a relationship between blood-cholesterol levels and the amount of fat consumed; however, the blood-cholesterol level bears little relationship to the amount of cholesterol consumed, most of the cholesterol in the body being produced by the body itself.

On the other hand, diets high in saturated fatty acids – chie?y animal fats such as red meat, butter and dripping – tend to raise the blood-cholesterol level; while foods high in unsaturated fatty acids – chie?y vegetable products such as olive and sun?ower oils, and oily ?sh such as mackerel and herring – tend to lower it. There is a tendency in western society to eat too much animal fat, and current health recommendations are for everyone to decrease saturated-fat intake, increase unsaturated-fat intake, increase daily exercise, and avoid obesity. This advice is particulary important for people with high blood-cholesterol levels, with diabetes mellitus, or with a history of coronary thrombosis (see HEART, DISEASES OF). As well as a low-cholesterol diet, people with high cholesterol values or arterial disease may be given cholesterol-reducing drugs such as STATINS, but this treatment requires full clinical assessment and ongoing medical monitoring. Recent research involving the world’s largest trial into the effects of treatment to lower concentrations of cholesterol in the blood showed that routine use of drugs such as statins reduced the incidence of heart attacks and strokes by one-third, even in people with normal levels of cholesterol. The research also showed that statins bene?ted women and the over-70s.... cholesterol

Dwar?sm, or short stature, refers to underdevelopment of the body. The condition, which has various causes, is not common. All children who by the age of ?ve years are at least what is technically known as ‘three standard deviations below the mean’ – well below average size for children of that age – should be referred for specialist advice. Among the causes are:

•genetic: familial; abnormalities of chromosomes, for example, TURNER’S SYNDROME; abnormal skeletal development; and failure of primary growth.

intrauterine growth retardation: maternal disorders; placental abnormalities; multiple fetuses.

constitutional delay in normal growth.

systemic conditions: nutritional de?ciencies; gastrointestinal absorption disorders; certain chronic diseases; psychosocial deprivation; endocrine malfunctions, including HYPOTHYROIDISM, CUSHING’S SYNDROME, RICKETS, dysfunction of the PITUITARY GLAND which produces growth hormone, the endocrine growth controller. Treatment of short stature is, where possible,

to remedy the cause: for example, children with hypothyroidism can be given THYROXINE. Children who are not growing properly should be referred for expert advice to determine the diagnosis and obtain appropriate curative or supportive treatments.... dwarfism

An autoimmune disorder in which the body’s immune system develops antibodies against its own thyroid gland cells. As a result, the thyroid gland cannot produce enough thyroid hormones, a condition known as hypothyroidism. The principal symptoms of Hashimoto’s thyroiditis are tiredness, muscle weakness, and weight gain, and the thyroid gland becomes enlarged.

Diagnosis is confirmed by blood tests.

Treatment is by thyroid hormone replacement therapy, which is life-long.... hashimoto’s thyroiditis

Metabolic disorders that are characterized by high levels of lipids in the blood. Hyperlipidaemias may be inherited or associated with another disorder, such as hypothyroidism, diabetes mellitus, kidney failure, or Cushing’s syndrome. They may also be a result of use of corticosteroid drugs. Hyperlipidaemias are associated with atherosclerosis and coronary artery disease.The signs depend on the type of hyperlipidaemia and may include fatty nodules in the skin or over joints, and a white line around the rim of the cornea.

Diagnosis depends on blood tests.

Treatment aims to reduce blood lipid levels, usually by a low-fat diet and lipid-lowering drugs.... hyperlipidaemias

Excessive limpness in infants, also known as floppy infant syndrome. Hypotonic babies cannot hold their limbs up against gravity and so tend to lie flat with their arms and legs splayed. Hypotonia may be caused by Down’s syndrome or hypothyroidism and may be

an early feature of cerebral palsy.

It occurs in disorders of the spinal cord, such as Werdnig–Hoffman disease, and in some children who have muscular dystrophy.... hypotonia in infants

A synthetic version of the thyroid hormone thyroxine, used to treat hypothyroidism. Side effects, such as rapid heartbeat and tremor, may occur if the initial dose is too high.... levothyroxine

A thyroid hormone used as replacement therapy in hypothyroidism. Liothyronine acts more quickly than levothyroxine and is cleared from the body more rapidly.... liothyronine

Abnormal enlargement of the tongue.

Macroglossia is a feature of Down’s syndrome, hypothyroidism, and acromegaly.

It is also caused by some tumours of the tongue, such as a haemangioma or a lymphangioma.... macroglossia

A condition in which there is thickening and coarsening of the skin and other body tissues (most noticeably

in the face). Myxoedema is usually due to hypothyroidism; in such cases, the condition is commonly accompanied by weight gain, hair loss, sensitivity to cold, and mental dullness. The term “myxoedema” is sometimes used for adult hypothyroidism.... myxoedema

Tiredness: a physiological state in which muscles become fatigued by the LACTIC ACID accumulating in them as the result of their activity. For the removal of lactic acid in the recovery phase of muscular contraction, oxygen is needed. If the supply of oxygen is not plentiful enough, or cannot keep pace with the work the muscle is doing, then lactic acid accumulates and fatigue results. There is also a nervous element in muscular fatigue: it is diminished by stimulation of the sympathetic nervous system. (See also MUSCLE.)

Chronic fatigue is a symptom of some illnesses such as ANAEMIA, CHRONIC FATIGUE SYNDROME (CFS), HYPOTHYROIDISM, MONONUCLEOSIS, MOTOR NEURONE DISEASE (MND), MYASTHENIA GRAVIS, MYALGIC ENCEPHALOMYELITIS (ME) and others. Some drugs may also produce a feeling of fatigue.... fatigue

Symptoms These vary, with pain and fatigue generally prominent, sometimes causing considerable disability. Patients can usually dress and wash independently but cannot cope with a job or household activities. Pain is mainly axial, but may affect any region. ANALGESICS, NONSTEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS) and local physical treatments are generally ine?ective.

Patients often have a poor sleep pattern, waking exhausted. Unexplained headache, urinary frequency and abdominal symptoms are common, but no cause has been found. Patients generally score highly on measures of anxiety and DEPRESSION. Fibromyalgia is not an ideal description; idiopathic di?use-pain syndrome and non-restorative sleep disorder are increasingly preferred terms.

Clinical ?ndings are generally unremarkable; most important is the presence of multiple hyperalgesic tender sites (e.g. low cervical spine, low lumbar spine, suboccipital muscle, mid upper trapezius, tennis-elbow sites, upper outer quadrants of buttocks, medial fat pad of knees). In ?bromyalgia, hyperalgesia (excessive discomfort) is widespread and symmetrical, but absent at sites normally non-tender. Claims by patients to be tender all over are more likely to be due to fabrication or psychiatric disturbance. OSTEOARTHRITIS and periarticular syndrome are much more common and should be excluded, together with other conditions, such as hypothyroidism (see THYROID GLAND, DISEASES OF), SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) and in?ammatory myopathy (see MUSCLES, DISORDERS OF), which may present with similar symptoms.

Cause There is no investigational evidence of in?ammatory, metabolic or structural abnormality, and the problem seems functional rather than pathological. SEROTONIN de?ciency has a signi?cant role in ?bromyalgia syndrome.

Management Controlled trials have con?rmed the usefulness of low-dose AMITRIPTYLINE or DOTHIEPIN together with a graded exercise programme to increase aerobic ?tness. How this works is still unclear; its e?cacy may be due to its normalising effects on the sleep centre or ‘pain gating’ (reduction of pain sensation) at the spinal-cord level. Prognosis is often poor. Nevertheless, suitable advice and training can help most patients to learn to cope better with their condition and avoid unnecessary investigations and drug treatments.... fibromyalgia syndrome

Linn.

Family: Fucaceae. (Laminaria sp.)

Habitat: On the shores of the United Kingdom, North Atlantic Ocean, North Pacific Coast of America; as a weed; found in Indian Ocean on the Manora Rocks. Allied species—F. distichus Linn., and F nodosus Linn. (Included in Glossary of Indian Medicinal Plants, CSIR, also in its second supplement.) F. nodosus is found in India along sea shores.

English: Bladderwrack, Black Tang, Rockweed, Kelp.

Action: Weed—one of the richest source of minerals, chiefly iodine, sodium, manganese, sulphur, silicon, zinc and copper. Effective against obesity, antirheumatic. Stimulates circulation of lymph. Endocrine gland stimulant. Allays onset of arteriosclerosis by maintaining elasticity of walls of blood vessels. Mild diuretic, bulk, laxative, antibiotic. High sodium content may reduce effectiveness of diuretics.

(The herb contains trace metal, particularly iodine from 0.03-1.0%. It may contain waste metals such as cadmium and strontium, when grown in a polluted environment. Variable iodine content and arsenic contamination make the herb unsafe.)

The herb should be used with caution in hyperthyroidism and hypothyroidism. Excess thyroid activity maybe aggravated by the iodine content of the herb; it may disrupt thyroid function. One gram of Bladderwrack might contain as much as 600 mcg iodine (Ingesting more than 150 mcg iodine per day may cause hyperthyroidism or exacerbate existing hyperthyroidism.) (Natural Medicines Comprehensive Database, 2007.)

Due to the antithrombin effects ofits fucan polysaccharides, consumption of the herb in cases of G1 bleeding disorders is contraindicated.

(Included among unapproved herbs by German Commission E.)... fucus vesiculosus

Abnormal paleness of the skin and mucous membranes, particularly noticeable in the face. Pallor is not always a symptom of disease. It may be due to a deficiency of the skin pigment melanin that may affect people who spend very little time in daylight. It is also a feature of albinism. In addition, pallor may be caused by constriction of small blood vessels in the skin, which may occur in response to shock, severe pain, injury, heavy blood loss, or fainting.Disorders that cause pallor include anaemia, pyelonephritis, kidney failure, and hypothyroidism. Lead poisoning is a rare cause.... pallor

A slow, but regular heart-rate (less than 60 beats per minute) caused by reduced electrical activity in the sinoatrial node. Sinus bradycardia is normal in athletes, but in others it may be caused by hypothyroidism, a myocardial infarction, or by drugs such as beta-blockers or digoxin.... sinus bradycardia

Inflammation of the thyroid gland.

Thyroiditis occurs in several different forms.

The most common is Hashimoto’s thyroiditis, an autoimmune disorder that results in hypothyroidism.

Less commonly, the inflammation is associated with a viral infection, or it may occur temporarily soon after childbirth; in both these cases, long-term damage to the gland is uncommon.... thyroiditis

Inability to speak normally. Temporary partial loss of voice commonly results from straining of the muscles of the larynx through overuse of the voice or from inflammation of the vocal cords in laryngitis. Persistent or recurrent voice loss may be due to polyps on the vocal cords, thickening of the cords in hypothyroidism, or interference with the nerve supply to the larynx muscles due to cancer of the larynx, thyroid gland, or oesophagus. Total loss of voice is rare and is usually of psychological origin. (See also hoarseness; larynx, disorders of.)... voice, loss of

An excess of fat in the blood, characterising a group of metabolic disorders. The two most important fats circulating in the blood are CHOLESTEROL and TRIGLYCERIDE. Raised blood levels of cholesterol predispose to ATHEROMA and coronary artery disease (see HEART, DISEASES OF); raised triglycerides predispose to pancreatitis (see PANCREAS, DISORDERS OF). Six types of hyperlipidaemia have been identi?ed, and diagnosis of the di?erent types depends upon blood tests to discover lipid levels. Some of the hyperlipidaemias are familial, and some are secondary to other diseases such as hypothyroidism (see THYROID GLAND, DISEASES OF), DIABETES MELLITUS, nephrotic syndrome and alcoholism.

Treatment There is evidence that therapy which lowers the lipid concentration reduces the progression of premature atheroma, particularly in those who suffer from the familial disorder. Treatment should include appropriate diets, usually food that is low in cholesterol and saturated fats. There are a number of drugs available for lowering the lipid content of the plasma, but these should be reserved for patients in whom severe hyperlipidaemia is inadequately controlled by weight reduction. Anion-exchange resins – clo?brate, beza?brate and gem?brozil, for example – and statins such as atorvastatin and simvastatin, as well as nicotinic acid, all lower plasma cholesterol and plasma triglyceride concentration through their e?ect on reducing the hepatic production of lipoproteins. Cholestyramine and colestipol, both of which are anion-exchange resins, bind bile salts in the gut and so decrease the absorption of the cholesterol that these bile salts contain – hence lowering plasma cholesterol concentrations. Probucol lowers plasma cholesterol concentrations by increasing the metabolism of low-density lipoproteins.

The statins (atorvastatin, cerivastatin, ?uvastatin, pravastatin and simvastatin) inhibit an enzyme involved in synthesising cholesterol, especially in the liver. They are more e?ective than anion-exchange resins in lowering LDL (low-density lipoprotein) cholesterol – a form of low-density cholesterol carried in the bloodstream, high levels of which are believed to be the main cause of atheroma. Statins are, however, less e?ective than the clo?brate group in reducing triglycerides and raising HDL (highdensity lipoprotein) cholesterol (high-density cholesterol).... hyperlipidaemia

Lethargy, or lassitude, means a loss of energy. It is a common presenting complaint both to general practitioners and to hospital consultants. It may have a physical cause or a psychological cause; it may be the result of inadequate rest, environmental noise, boredom, insomnia or recent illness. Certain medicinal drugs can cause lethargy, the most common being beta blockers (see BETA-ADRENOCEPTOR-BLOCKING DRUGS) and DIURETICS, and drugs of abuse may also be a cause (see DEPENDENCE). The common psychosocial problems producing lethargy are DEPRESSION and anxiety.

If the patient with lethargy runs a fever, the di?erential diagnosis is that of a PUO (pyrexia of unknown origin). Many patients with fatigue can establish the onset of the symptom to a febrile illness even though they no longer run a fever. The lethargy that follows some viral infecions, such as HEPATITIS A and glandular fever (see MONONUCLEOSIS) is well recognised; MYALGIC ENCEPHALOMYELITIS (ME) or chronic fatigue syndrome is another disorder associated with lethargy and tiredness. Organic causes of lethargy include ANAEMIA, malnutrition and hypothyroidism (see THYROID GLAND, DISEASES OF). Some of these patients have a true depressive illness and their presentation and response to treatment is little di?erent from that of sufferers of any other depressive illness, URAEMIA, alcoholism and DIABETES MELLITUS.... lethargy

n. the appearance of calcific material in joint cartilage, most commonly an incidental finding on X-ray of the knees in elderly patients and usually causing no symptoms. Calcification of cartilage may also be seen at the shoulder and in the fibrocartilage of the wrist. It may be associated with osteoarthritis. It is also seen less commonly in several other disorders, including Wilson’s disease, pseudogout, hyperparathyroidism, hypothyroidism, and haemochromatosis.... chondrocalcinosis

n. a collection of inherited disorders of thyroid hormone synthesis resulting in low levels of *thyroxine and *triiodothyronine and high levels of *thyroid-stimulating hormone, with consequent *goitre formation. The result may be *cretinism with a goitre or milder forms of *hypothyroidism with a goitre. Several different stages of the production pathway for thyroid hormones can be affected.... dyshormonogenesis

(sick euthyroid syndrome) a syndrome characterized by alteration in the thyroid function tests in which the level of triiodothyronine is markedly reduced, thyroxine is slightly reduced, and thyroid-stimulating hormone is reduced or normal. This syndrome is commonly seen in nonthyroidal illness, due to altered metabolism and transport of the thyroid hormones, but can be mistaken for secondary *hypothyroidism.... euthyroid sick syndrome

A condition in which the energy stores of the body (mainly fat) are too large. It is a prevalent nutritional disorder in prosperous countries – increasingly so among children and young people. The Quetelet Index or BODY MASS INDEX, which relates weight in kilograms (W) to height2 in metres (H2), is a widely accepted way of classifying obesity in adults according to severity. For example:

Grade of obesity

BMI (W/H2) III >40 II 30–40 I 25–29·9 not obese <25

Causes Whatever the causes of obesity, the fact remains that energy intake (in the form of food and drink) must exceed energy output (in the form of activity and exercise) over a suf?ciently long period of time.

Obesity tends to aggregate in families. This has led to the suggestion that some people inherit a ‘thrifty’ gene which predisposes them to obesity in later life by lowering their energy output. Indeed, patients often attribute their obesity to such a metabolic defect. Total energy output is made up of the resting metabolic rate (RMR), which represents about 70 per cent of the total; the energy cost of physical activity; and thermogenesis, i.e. the increase in energy output in response to food intake, cold exposure, some drugs and psychological in?uences. In general, obese people are consistently found to have a higher RMR and total energy output, per person – and also when expressed against fat-free mass – than do their lean counterparts. Most obese people do not appear to have a reduced capacity for thermogenesis. Although a genetic component to obesity remains a possibility, it is unlikely to be great or to prevent weight loss from being possible in most patients by reducing energy intake. Environmental in?uences are believed to be more important in explaining the familial association in obesity.

An inactive lifestyle plays a minor role in the development of obesity, but it is unclear whether people are obese because they are inactive or are inactive because they are obese. For the majority of obese people, the explanation must lie in an excessive energy intake. Unfortunately, it is di?cult to demonstrate this directly since the methods used to assess how much people eat are unreliable. For most obese people it seems likely that the defect lies in their failure to regulate energy intake in response to a variety of cognitive factors (e.g. ease of ?tting of clothes) in the long term.

Unfortunately, it can be possible to identify by the time of their ?rst birthday, many of the children destined to be obese.

Rarely, obesity has an endocrine basis and is caused by hypothyroidism (see under THYROID GLAND, DISEASES OF), HYPOPITUITARISM, HYPOGONADISM or CUSHING’S SYNDROME.

Symptoms Obesity has adverse effects on MORBIDITY and mortality (see DEATH RATE) which are greatest in young adults and increase with the severity of obesity. It is associated with an increased mortality and/or morbidity from cardiovascular disease, non-insulin-dependent diabetes mellitus, diseases of the gall-bladder, osteoarthritis, hernia, gout and possibly certain cancers (i.e. colon, rectum and prostate in men, and breast, ovary, endometrium and cervix in women). Menstrual irregularities and ovulatory failure are often experienced by obese women. Obese people are also at greater risk when they undergo surgery. With the exception of gallstone formation, weight loss will reduce these health risks.

Treatment Creation of an energy de?cit is essential for weight loss to occur, so the initial line of treatment is a slimming diet. An average de?cit of 1,000 kcal/day (see CALORIE) will produce a loss of 1 kg of fat/week and should be aimed for. Theoretically, this can be achieved by increasing energy expenditure or reducing energy intake. In practice, a low-energy diet is the usual form of treatment since attempts to increase energy expenditure, either by physical exercise or a thermogenic drug, are relatively ine?ective.

Anorectic drugs, gastric stapling and jaw-wiring are sometimes used to treat severe obesity. They are said to aid compliance with a low-energy diet by either reducing hunger (anorectic drugs) or limiting the amount of food the patient can eat. Unfortunately, the long-term e?ectiveness of gastric stapling is not known, and it is debatable whether the modest reduction in weight achieved by use of anorectic drugs is worthwhile – although a new drug, ORLISTAT, is becoming available that reduces the amount of fat absorbed from food in the gastrointestinal tract. For some grossly obese patients, jaw-wiring can be helpful, but a regain of weight once the wires are removed must be prevented. These procedures carry a risk, so should be done only if an individual’s health is in danger.... obesity

ACROMEGALY or gigantism is the result of the overactivity of, or tumour formation of cells in, the adenohypophysis which produces GROWTH HORMONE (see also PITUITARY GLAND). If this overactivity occurs after growth has ceased, acromegaly arises, in which there is gross overgrowth of the ears, nose, jaws, and hands and feet. DWARFISM may be due to lack of growth hormone.

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

(heel-prick blood test) a blood test performed on all newborn babies at the end of the first week of life. The blood is obtained by pricking the heel of the baby. The test can detect several *inborn errors of metabolism (including *phenylketonuria) and *hypothyroidism; it can also be used for detecting *cystic fibrosis, although this is not routinely offered. [R. Guthrie (1916–95), US paediatrician]... guthrie test

Body temperature is the result of a balance of heat-generating forces, chie?y METABOLISM and muscular activity, and heat-loss, mainly from blood circulation through and evaporation from the skin and lungs. The physiological process of homeostasis – a neurological and hormonal feedback mechanism – maintains the healthy person’s body at the correct temperature. Disturbance of temperature, as in disease, may be caused by impairment of any of these bodily functions, or by malfunction of the controlling centre in the brain.

In humans the ‘normal’ temperature is around 37 °C (98·4 °F). It may rise as high as 43 °C or fall to 32 °C in various conditions, but the risk to life is only serious above 41 °C or below 35 °C.

Fall in temperature may accompany major loss of blood, starvation, and the state of collapse (see SHOCK) which may occur in severe FEVER and other acute conditions. Certain chronic diseases, notably hypothyroidism (see THYROID GLAND, DISEASES OF), are generally accompanied by a subnormal temperature. Increased temperature is a characteristic of many acute diseases, particularly infections; indeed, many diseases have a characteristic pattern that enables a provisional diagnosis to be made or acts as a warning of possible complications. In most cases the temperature gradually abates as the patient recovers, but in others, such as PNEUMONIA and TYPHUS FEVER, the untreated disease ends rapidly by a CRISIS in which the temperature falls, perspiration breaks out, the pulse rate falls, and breathing becomes quieter. This crisis is often preceded by an increase in symptoms, including an epicritical rise in temperature.

Body temperature is usually measured on the Celsius scale, on a thermometer reading from 35 °C to 43·3 °C. Measurement may be taken in the mouth (under the tongue), in the armpit, the external ear canal or (occasionally in infants) in the rectum. (See also THERMOMETER.)

Treatment Abnormally low temperatures may be treated by application of external heat, or reduction of heat loss from the body surface. High temperature may be treated in various ways, apart from the primary treatment of the underlying condition. Treatment of hyperthermia or hypothermia should ensure a gradual return to normal temperature (see ANTIPYRETICS.... temperature

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

This occurs in one in 2,500 live female births. It is caused by either the absence of or an abnormality in one of the two X CHROMOSOMES. Classical Turner’s syndrome is a complete deletion of one X so that the karyotype is 45XO. Half of the people with Turner’s syndrome have MOSAICISM with a mixture of Turner cells and normal cells, or other abnormalities of the X chromosome such as partial deletions or a ring X. They are females, both in appearance and sexually; clinical features are variable and include short stature, with ?nal height between 1·295 m and 1·575 m, and ovarian failure. Other clinical features may include a short neck, webbing of the neck, increased carrying angle at the elbow (cubitus valgus), widely spaced nipples, cardiovascular abnormalities (of which the commonest is coarctation of the aorta [about 10 per cent]), morphological abnormalities of the kidneys (including horseshoe kidney and abnormalities of the pelviureteric tracts), recurrent otitis media (see under EAR, DISEASES OF), squints, increased incidence of pigmented naevi (see NAEVUS), hypothyroidism (see under THYROID, DISEASES OF) and DIABETES MELLITUS. Intelligence is across the normal range, although there are speci?c learning defects which are related to hand-eye coordination and spatial awareness.

Patients with Turner’s syndrome may require therapeutic help throughout their life. In early childhood this may revolve around surgical correction of cardiovascular disease and treatment to improve growth. Usually, PUBERTY will need to be induced with oestrogen therapy (see OESTROGENS). In adult life, problems of oestrogen therapy, prevention of osteoporosis (see under BONE, DISORDERS OF), assessment and treatment of HYPERTENSION and assisted fertility predominate. For the address of the UK Turner Syndrome Society, see Appendix 2.... turner’s syndrome

(TSH, thyrotrophin) a hormone, synthesized and secreted by the anterior pituitary gland under the control of *thyrotrophin-releasing hormone, that stimulates activity of the thyroid gland. Raised levels of TSH are found in primary *hypothyroidism. Normal or low TSH levels in the presence of a low serum thyroxine are found in secondary hypothyroidism and the *euthyroid sick syndrome.... thyroid-stimulating hormone

autoantibodies targeted against the *thyroid-stimulating hormone (TSH) receptor of the thyroid cells. They can activate the TSH receptor, leading to the hyperthyroidism of *Graves’ disease, or they can block the TSH receptor, causing *hypothyroidism.... tsh receptor antibodies

Peumus boldus, Molina. French: Boldu. German: Chilenischer Boldobaum. Italian: Boldo. Part used: leaves.

Constituents: Peumus bollidus, boldine. Grows in Central Chile where it is used against liver diseases and gall stones.

Action. Cholagogue, liver tonic, diuretic, urinary antiseptic, laxative (mild), choleretic, anti-obesity, liver-protector, anti-inflammatory, choleretic.

Uses: Inflammation of the gall bladder, gall stone, biliary colic, infective cystitis, hypothyroidism, fluid retention.

Combination. With Barberry and Fringe Tree for gall stones and hepatic disease BHP (1983). Preparations. Thrice daily.

Tea. Quarter of a teaspoon to each cup boiling water; infuse 15 minutes. Dose: half a cup. Liquid extract. 1-5 drops in water.

Tincture BHP (1983) 1:10 in 60 per cent alcohol. Dose: 0.5-2ml in water. Powder. (capsules) 250mg (one 00 capsule) or one-sixth teaspoon. ... boldo

A conflict is created when natural body rhythms do not synchronise with real time. Sufferers feel wide awake at night and cannot sleep during the day. Treatment is focussed on the pineal gland – the biological clock.

Symptoms: lethargy, disorientation, clinical depression and tiredness associated with long-haul flights. Treatment. Herbs for pushing forward (or back) the internal clock so that biological time accords with chronological time: Ginseng, Garlic, Gotu Kola, Kola, Capsicum. These may be supported by a good multivitamin capsule. Ginseng is a melatonin stimulant. Treat transient hypothyroidism.

Topical. Inhalant: aromatherapy oil – Rosemary.

Diet. Day before ‘take-off’ should be a ‘feast’ day, but the day of departure should be a ‘fast’ day. Coffee, tea and other caffeine-containing beverages should be taken only in the evenings of ‘fast’ days when going east, and in the mornings going west. Circadian disturbance is more easily adjusted on ‘fast’ days. This regime assists the production of melatonin, a natural hormone of the pineal gland which manipulates the body’s response to the light/dark cycle. Avoid alcohol.

Supplements. Daily. Vitamin B6 10mg; Vitamin C 2g; Vitamin E 400iu. Magnesium, Selenium, Zinc.

Note: On day of departure change watch to the time at your destination. During the flight eat only if it is daytime there. Take plenty of fluids. On arrival the body clock is already adjusted to local time – go to bed. ... jet lag

Spontaneous, persistent production of milk by a woman who is not pregnant or lactating (see lactation), or, very rarely, by a man.

Lactation is initiated by a rise in the level of prolactin, a hormone produced by the pituitary gland. Galactorrhoea is caused by excessive secretion of prolactin due to a pituitary tumour or otherendocrine disease, such as hypothyroidism. Some antipsychotic drugs may also cause excessive secretion. Treatment with bromocriptine suppresses prolactin production, but the underlying cause may also need treatment. galactosaemia A rare, inherited condition in which the body is unable to convert the sugar galactose into glucose due to the absence of a liver enzyme. It causes no symptoms at birth, but jaundice, diarrhoea, and vomiting soon develop and the baby fails to gain weight. Untreated, the condition results in liver disease, cataract, and learning difficulties. The diagnosis is confirmed by urine and blood tests. The major source of galactose is the milk sugar lactose. Lactosefree milk must be used throughout life. gallbladder A small, pear-shaped sac situated under the liver that stores bile. Bile, produced by the liver, passes into the gallbladder via the hepatic and cystic ducts. It is released into the intestine via the common bile duct.... galactorrhoea

A thread-like structure composed of dead cells containing keratin, a fibrous protein. The root of each hair is embedded in a tiny pit in the dermis layer of the skin called a hair follicle. Each shaft of hair consists of a spongy semihollow core (the medulla), a surrounding layer of long, thin fibres (the cortex), and, on the outside, several layers of overlapping cells (the cuticle). While a hair is growing, the root is enclosed by tissue called a bulb, which supplies the hair with keratin. Once the hair has stopped growing, the bulb retracts from the root and the hair eventually falls out.

Hair is involved in the regulation of body temperature (known as thermoregulation). If the body is too cold, arrector pili muscles in the skin contract, pulling the hairs upright to form goose pimples. Erect hairs trap an insulating layer of air next to the skin.Brittle hair may be due to excessive styling, hypothyroidism, or severe vitamin or mineral deficiency. Very dry hair

can be caused by malnutrition. Ingrown hairs occur when the free-growing end of the hair penetrates the skin near the follicle, which may cause inflammation. (See also hirsutism; hypertrichosis.)... hair

A rough, husky, or croaking voice. Short-lived hoarseness is often due to overuse of the voice, which strains the muscles in the larynx. It is also commonly caused by inflammation of the vocal cords in acute laryngitis. Persistent hoarseness may be due to chronic irritation of the larynx, which can be caused by smoking, excessive consumption of alcohol, chronic bronchitis, or constant dripping of mucus from the nasal passages. Polyps on the vocal cords may also cause hoarseness. In people with hypothyroidism, hoarseness can result from formation of tissue on the vocal cords. In young children, hoarseness may be a symptom of croup. Occasionally persistent hoarseness in adults has a more serious cause, such as cancer of the larynx (see larynx, cancer of), thyroid cancer, or lung cancer.

Resting the voice helps in strain- or laryngitis- related cases. If hoarseness persists for more than 2 weeks, a doctor should be consulted. A laryngoscopy may be performed to exclude a serious underlying cause.... hoarseness

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

Yellowing of the skin and whites of the eyes in newborn babies, due to accumulation of bilirubin in the blood. It usually results from the liver being immature and unable to excrete bilirubin efficiently. This form of jaundice is usually harmless and disappears within a week. Rarely, severe or persistent neonatal jaundice is caused by haemolytic disease of the newborn, G6PD deficiency, hepatitis, hypothyroidism, biliary atresia, or infection.

Jaundiced babies usually require extra fluids and may be treated with phototherapy.

Exchange transfusion (see blood transfusion) may be needed in severe cases.

If severe neonatal jaundice is not treated promptly, kernicterus may occur.... jaundice, neonatal

A gross distension (enlargement) of the colon, usually accompanied by severe, chronic constipation.

In children, the main causes of megacolon are anal fissures, Hirschsprung’s disease, and psychological factors that may have arisen during toilet-training. In elderly people, causes include the long-term use of strong laxative drugs. People suffering from chronic depression or schizophrenia often have megacolon. Other, rarer causes include hypothyroidism, spinal injury, and drugs such as morphine and codeine.

Megacolon causes constipation and abdominal bloating. Associated loss of appetite may lead to weight loss. Diarrhoea may result if semi-liquid faeces leak around the obstructing hard faeces.

Diagnosis is made by proctoscopy, barium X-ray examination, and tests of bowel muscle function. If Hirschsprung’s disease is suspected, biopsy of the large intestine may be performed. Impacted faeces are often removed using enemas. In severe cases, the faeces must be removed manually.... megacolon

A height significantly below the normal range for a person’s age. Short stature in children is often due to hereditary factors or slow bone growth. In most cases, growth eventually speeds up, resulting in normal adult height. Less commonly, it is due to a specific disorder such as bone disease (as in untreated rickets or achondroplasia) or certain hormonal disorders such as growth hormone deficiency and hypothyroidism. Emotional deprivation, chronic malnutrition and malabsorption can also limit growth. Certain chromosomal disorders cause short stature; stunting occurs in Down’s syndrome, and the pubertal growth spurt is absent in Turner’s syndrome. Other causes of restricted growth in children include prolonged use of corticosteroids and anticancer drugs. Severe untreated respiratory disease or congenital heart disease can also cause short stature.

An affected child’s growth rate is monitored by regular measurement of height.

X-rays and blood tests may help identify an underlying cause, which will then be treated.

Growth hormone is given for hormone deficiency, and also to treat short stature due to disorders such as Turner’s syndrome.

(See also growth, childhood.)... short stature

Disorders of the thyroid gland may cause hyperthyroidism, hypothyroidism, or enlargement or distortion of the gland. Myxoedema, Graves’ disease, and Hashimoto’s thyroiditis are common disorders. Goitre may sometimes occur with no accompanying abnormality of thyroid function. In rare cases, the gland is absent at birth, producing severe cretinism. Sometimes it develops in an abnormal position in the neck, causing, in rare cases, difficulty in swallowing or breathing.

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

a life-threatening condition due to severe *hypothyroidism, which is often precipitated by an acute event, such as surgery, prolonged exposure to cold, infection, trauma, other severe illness, or sedative drugs. It manifests as hypothermia, slowing of the heart rate with a reduction in blood pressure and sometimes heart failure, pleural and peritoneal effusions, urinary retention, and a gradually reduced conscious state resulting in coma. Blood tests show hypothyroidism, *hyponatraemia, hypercholesterolaemia, retention of carbon dioxide, and anaemia. Treatment is with intravenous *thyroxine at a high dosage until the patient wakes up, when tablets can be administered. Support on a ventilator and intravenous fluids may be needed. Active slow rewarming should be undertaken.... myxoedema coma

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