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yellow fever

Viral infection prevalent in Central and South America and Africa, which occurs in Western Europe in travellers from these areas. The virus multiplies in the Aedes mosquito, and for the rest of its life span the insect can transmit the virus to man. There are two kinds of yellow fever, the urban variety, in which…

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Vitamin deficiency

Because vitamins do not form a coherent group, this term includes a number of different conditions with different causes. Vitamin deficiency is by no means always the consequence of inadequate nutrition. Two principal groups should be distinguished: vitamins soluble in fat (A, D, E and K) and those soluble in water (the rest). The following…

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Vitiligo

Disorder in the pigmentation of the skin. Pale patches occur as a result of the disappearance of pigment, mainly on the backs of the hands, the face and around the anus. They can form over a period of a few days. The spots are usually only noticed when they are already some centimetres in size…

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Volvulus

Twisting of an intestinal loop around its own axis, possible because practically all the small intestine and a small section of the large intestine (sigmoid colon) are attached to the abdominal wall only by a single membrane containing the intestinal blood vessels. Volvulus is a very rare condition, usually congenital in children; volvulus of the…

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vomiting

Forcible regurgitation of the contents of the stomach. Vomiting has various causes, which may lie in the abdomen, the stomach and intestine itself, the brain, or other disorders that stimulate the brain. Psychological causes should not be ruled out. Brain conditions can cause vomiting by stimulating the vomiting centres in the brain, and this can…

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Von Recklinghausen’s disease

Hereditary disorder involving characteristic skin patches and tumours of the skin and nerve tissue. In the nerves of spinal cord and brain, neurinomas and neurofibromas usually occur; they are normally both benign tumours. They can be very close to the spinal cord or brain, and cause discomfort by pressure. On rare occasions neurofibromas can become…

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wart (verruca)

Benign swelling of the skin that results from a virus infection. Warts measure anything from a few millimetres to a few centimetres in diameter and can occur anywhere on the skin. A wart begins as a small excrescence of the upper layers of the skin. This swelling expands into a small growth typically resembling a…

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Weight loss

Persistent decrease in body weight, in medical terms including only abnormal cases, not justifiable or desired weight loss. Weight loss can have many causes, by no means all of them dependent on conditions of the digestive organs. The conditions which may be responsible can be divided into two principal groups: malabsorption (difficulties in absorbing food…

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Weil’s disease (leptospirosis)

Disease caused by the bacterium Leptospira icterohaemorrhagiae, which usually infects rodents living in the wild. This disease occurs the world over. The animals, mainly brown rats, excrete the bacterium along with their urine. The bacteria survive better in fresh water and the chances of humans becoming infected are greatest in a damp area where there…

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welder’s eye

Acute inflammation of the cornea as a result of exposure of the eye to ultraviolet radiation, as from arc welding and UV lamps; a form of ophthalmia. It causes damage to the cornea which becomes evident 6 to 12 hours after exposure to the UV light. The eye can also be exposed to excessive quantities…

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Whitlow

Inflammation of the subcutaneous tissue of the fingers which has spread to the bone of the phalanx. The condition is caused by bacteria (usually in association with an inadequately disinfected cut) which establish themselves in the marrow of the phalanx bones. The symptoms are pain in the affected finger and sometimes slight fever, and a…

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Vertebral disc disorders

Conditions relating to the elastic discs of cartilage between the spinal vertebrae. The spinal column derives its flexilibity from these discs. These disorders are frequently accompanied by vertebral conditions. They usually lead to a restriction in the mobility of the spinal column and are often combined with pain. The best-known vertebral disc condition is dorsal…

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Worms

Millions of people are infested by parasitic worms, although in Europe parasitic infestations are mainly introduced by tourists and foreign employees. There are three major groups of worms: roundworms, flukes and tapeworms. Males and females occur only in round worms; the other worms are hermaphroditic, having both male and female sex organs. The part of…

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Vertigo

Collective name for a number of sensations of movement, dizziness or a feeling of lightheadedness. The sensation can be of spinning or falling away, and is caused by disorders of the inner ear, of the eighth cranial nerve (which carries stimuli from the auditory organs and the organs of balance), the brain stem or the…

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Xerophthalmia

Abnormality in which the secretion of tears is reduced, so that the cornea and conjunctiva of the eye are not sufficiently moist. The symptoms consist of irritation, pain and redness. The absence of lachrymal fluid may cause damage to the cornea. In one form of xerophthalmia, Shigren’s syndrome, the secretion of fluid by all the…

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Vincent’s angina

Inflammation of the tonsils and often also of surrounding mouth and throat tissue by bacteria normally present in the mouth, but which cause serious infection in the event of reduced resistance or serious nutritional deficiencies. The usual complaints are pain in the mouth and difficulty in swallowing, sometimes with general malaise and fever. There is…

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virilism

Appearance of male external sexual characteristics in a girl or woman. This takes place under the influence of male sex hormones (androgens). The clitoris becomes enlarged, and hair distribution resembles a man’s (hirsutism), with hair on the chest and face. The voice deepens, the breasts either do not develop or become smaller, and menstruation does…

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Uterine polyp

Benign protrusion of mucous membrane inside the womb, sometimes large enough to protrude through the cervix. Polyps cause a watery discharge containing blood, sometimes bleeding during intercourse (so-called contact bleeding), also excessive menstrual flow and painful menstruation, because the womb tries to eject the polyp. Polyps protruding from the neck of the womb.

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uterus, prolapsed

Condition in which the uterus (womb) hangs too low in the vagina, or sometimes protrudes from it, particularly after the menopause, and often connected with an earlier difficult childbirth. The prolapsed womb can also pull on the bladder, causing bladder complaints. Prolapse gives a heavy feeling in the lower abdomen, and risk of bladder infection…

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Vagina, atrophy of

Shrinkage of the mucous membrane lining of the vagina. After the menopause the oestrogen production of the ovaries decreases. All the internal sexual organs become smaller and the layer of mucous membrane in the vagina becomes thinner. If the ovaries are removed or irradiated, the same occurs because no oestrogens are produced. The reduced layer…

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Vagina, disorders of

In rare cases the vagina is missing altogether; this condition is usually accompanied by various congenital disorders. Congenital cysts occur regularly in the wall of the vagina and are harmless. A septum can also occur in the vagina. Sometimes the hymen is rigid and has no opening, preventing the passage of menstrual blood. Such disorders…

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Vaginal discharge

The sexually mature vagina is kept moist by a discharge that originates from the vaginal wall and the cervix; its quantity and thickness vary with the menstrual cycle. A large quantity of clear mucus is produced during ovulation and discharge also increases before menstruation. In the vagina there are bacteria which form lactic acid and…

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Vaginismus

Involuntary contraction of the muscles around the opening of the vagina which prevent penetration by the penis during intercourse, often leading to frustrations and loss of libido Some women are able to find satisfaction in other sexual activities and attain orgasm. There are various causes, such as fear of sexual intercourse because of an unpleasant…

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Vaginitis

Infection of the vaginal mucous membrane. One of the first symptoms is increased secretion and a white discharge, together with itching and smarting. The nature of the secretion, the colour, the smell if any, and the density, help to determine the cause of the inflammation. Diagnosis is by vaginal examination with a speculum and microscopic…

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Varicocele

Abnormality of the blood vessels which drain the testis, a kind of varicose vein, nearly always occurring on the left side. The cause is increased pressure in the veins below the testicle, particularly when the patient is standing up. The patient often does not notice the vario-cele but sometimes suffers from a heavy feeling in…

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Varicose veins

Abnormally dilated and tortuous veins, usually occurring in the legs. A vein can dilate if blood pressure increases, for example because the valves in the vein are not functioning properly, or because flow of blood out of the vein is restricted. The original condition is also important: some people have leg veins with naturally less…

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Venereal diseases

Contagious diseases transmitted by sexual contact, also known as sexually transmitted diseases. Most involve inflammation of the skin and mucous membranes. Besides well-known disorders such as syphillis and gonorrhoea there are many others now known to fall into this category, such as genital herpes, or conditions like lymphogranuloma venereum and granuloma inguinale. Disorders such as…

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urethritis

Inflammation of the urethra, the tube that carries urine from the bladder. A distinction is usually made between inflammation caused by gonorrhoea and the normal form, which is more common; in 25 per cent of such cases no cause can be found (non-specific urethritis, NSU). Almost all forms can be transmitted by sexual intercourse. The…

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Urinary disorders

Abnormalities in the quantity and/or composition of the urine. Normally, 1 to 2 litres of urine are produced daily. When less than 100 ml are produced, the condition is known as anuria. Low urination can also be the consequence of urine retention. Frequent urination is usually the result of cystitis. Abnormally high urine production occurs…

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Urticaria (nettlerash)

Itchy skin condition consisting of pink raised patches (urticae), which can occur suddenly; they disappear within a few days. Some people get nettlerash after eating certain foods, notoriously strawberries and chocolate, and some medicines can cause it. The condition can also accompany certain infections, both bacterial and viral, or worm infestation. There are also numerous…

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Uterine myoma

Benign tumour of muscle fibres in the wall of the womb. Uterine myomas usually occur in the muscular wall of the uterus itself (intramural), but they may also be located below the layer of mucous membrane (submucous) or below the capsule on the outside edge (subserous). The myoma grows in the direction of least resistance…

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Trench fever

Infection caused by Rickettsia quintana and transmitted by lice. Rickettsiae have characteristics of both viruses and bacteria, and the various forms cause illnesses with fever and skin rashes as their most important manifestations (including Q fever and typhus). They are transmitted by ticks, lice, mites or fleas, which explains the prevalence of the disease at…

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trichomoniasis

Infestation by a flagellate protozoan. This parasite has a world-wide distribution and women aged between 30 and 50 are the group mostly affected. Three kinds of trichomoniasis occur in humans, but only can cause symptoms. Most people who are infested are not troubled by the parasite and are carriers. Symptoms arise when the numbers of…

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Trichuriasis

Infestation with nematode worms of the genus Trichuris. They are 3-5 cm long and have a very thin front portion and a fat rear one containing the reproductive organs. They live for roughly eight years. The worms occur throughout the world: approximately 350 million people are infested. At the junction of the large and small…

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Tuberculosis

An infectious disease caused by the tubercle bacillus This bacterium was discovered by Robert Koch in 1882 and identified as being the causative agent of TB. Tuberculosis was formerly regarded as a manifestation of extreme physical decline as a result of malnutrition, poor hygiene and poverty, and it was known as (galloping) consumption or phthisis…

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Turner’s syndrome

A congenital abnormality in which a sex chromosome is missing. The woman has only one X-chromosome instead of two (or one chromosome and part of the second X-chromosome). This abnormality occurs during, or frequently after, the fertilization of the ovum. Women suffering from this syndrome are frequently short, have a short and wide neck, and…

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Typhoid fever

A serious infection caused by the bacterium Salmonella typhi. A similar clinical picture can be caused by the agent responsible for a form of paratyphoid. Infection can be transmitted by unboiled milk, water or by food infected by a carrier. The disease begins after an incubation period of about 7 to 14 days, with headaches,…

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tooth abscess

Inflammation of the part of a tooth where it enters the jawbone. It is often a complication of dental caries (decay). If a tooth is affected by caries, the process can be halted only by completely removing the decayed material and filling the space with a suitable substitute. If this is not done, inflammation arises…

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ulcer

Deep defect in the skin or mucous membrane, formed by the death of tissue. An ulcer shows little tendency to recover, in contrast to a wound which heals much more easily. Skin ulcers occur regularly, and have very varied causes. Bacteria, parasites, fungi etc. can cause ulcers. Examples are leprosy, yaws, leishmaniasis and syphilis. Disorders…

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Ulcerative colitis

Chronic inflammation and ulceration of the large intestine, without specific cause such as a bacterium or virus, often occurring in older children and young adults, but sometimes in later life. Ulcerative colitis is probably an autoimmune disease: the body produces defences against its own tissue. Psychological factors may also be involved, but this is doubted…

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Toxoplasmosis

Infestation by the widespread microorganism Toxoplasma gondii. Something like half the world’s population has the infestation, usually without displaying any symptoms. Many infected mammals and birds also act as hosts. The sexual development of the parasite takes place in a cat, the eggs being laid in the cat’s intestinal wall and being eliminated from the…