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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

Wernicke’s disease

Serious disorder caused by a deficiency of vitamin B,. It leads to haemorrhages in the brain stem and certain low-lying parts of the brain. The chief cause is failure to eat properly because of alcoholism. The symptoms include diplopia (double vision) caused by paralysis of the eye muscles and by pressure on the eyeballs. Other … Read more

ventricular septal defect

Hole in the septum between the heart’s ventricles. Ventricular septum defect is a congenital heart disorder; only in exceptional cases does it occur spontaneously, for example after a heart attack in which part of the septum dies. The consequence of a congenital ventricular septum defect is that blood flows from the left ventricle (where blood … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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.

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

Tricuspid valve, disorders of

A condition of the heart valve between the right auricle and the right ventricle. The function of the tricuspid valve is to prevent blood from flowing back from the ventricle to the auricle during the heart contraction of systole. Stricture (stenosis) of the tricuspid valve is rare. Leakage (insufficiency) of the valve can occur as … Read more

Trigeminal neuralgia

Facial pain caused by irritation of one or more branches of the trigeminal nerve. This is the sensory cranial nerve which innervates the face. Pain in the trigeminal nerve occurs mainly in older people. It is characterized by various sharp twinges lasting a few seconds, in the area of one cheek or jaw. These attacks … Read more

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 … Read more

tubular necrosis, acute

Sudden loss of kidney tubules, with resultant kidney failure. Acute tubule necrosis can be caused by a reduction in the supply of blood and oxygen to the kidneys, and also by poisonous substances such as mercury, carbon tetrachloride and some antibiotics. The excretion of large quantities of haemoglobin in the urine, such as after the … Read more

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 … Read more

Tonsils, enlargement of

Enlarged tonsils are usually caused by viral or bacterial infection, in the latter case often associated with fever, sore throat and enlarged lymph nodes in the neck. The condition occurs in tonsillitis and, among others, in glandular fever. The tonsils have a protective function against viruses and bacteria, but can lose this, and become a … Read more

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, … Read more

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 … Read more

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 … Read more

Toxic shock syndrome

A condition mainly seen in young women who use tampons during menstruation, which gave rise to the name ‘tampon disease. However, the phenomenon also occurs without any tampons being used (15 per cent of cases also occur in children). It is caused by bacterial toxins which may be released in the case of certain infections … Read more

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 … Read more

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 … Read more