Inability to recognize people or things despite intact sensory organs, caused by brain damage, cerebral haemorrhage, cerebral infarction, a tumour or an accident. The patient cannot make sense of anything he sees, hears or feels. Usually not all the senses are affected, but perhaps just the sense of touch. If the big toe is affected … Read more

Anaemia, pernicious

Anaemia caused by vitamin B,2 deficiency, needed for the production of red blood cells. Vitamin B,: can be absorbed from food only with the assistance of a substance found in the gastric juices, and deficiency is usually caused by an inadequate quantity of this substance in the stomach as a result of chronic inflammation or … Read more


Deficiency of granular leucocytes, a particular kind of white blood cell so-called because under the microscope they seem to contain white granules. Their function is to remove harmful bacteria, and agranulocytosis reduces the body’s defences against bacteria. The condition can occur for no known reason as an allergic reaction to particular medicines, such as certain … Read more


This article deals with the disorder known medically as anaesthesia, not with the techniques of using substances (anaesthetics) to prevent pain during treatment. Medically, anaesthesia involves the loss of sensation in the skin, causing an inability to experience touch, temperature changes or pain. Feeling in the skin consists of the coarse sense of touch, and … Read more

AIDS (acquired immune deficiency syndrome)

AIDS is a disease that causes the body’s immune system to fail to function against various bacteria, fungi and viruses. The disease is transmitted by a virus present in the blood and semen of patients suffering from AIDS. The virus is not found universally in the population, but is confined to certain groups. These so-called … Read more

Anal fissure

Longitudinal fissure in the anal mucous membrane, caused among other things by chronic hardness of the faeces or by haemorrhoids. Symptoms occur above all during defecation: severe, convulsive pain and loss of blood. The pain can persist for some time. The lost blood is not mixed with the faeces, is bright red, and the loss … Read more

Anal fistula

Passage forming a connection between the anal mucous membrane and the skin around the anus, usually caused by an abscess directly above the anus. Rectal fistulas can be caused by other conditions such as ulcerative colitis, Conn’s syndrome, tuberculosis of the rectum or a tumour. A fistula is characterized by an opening in the skin … Read more


Particular form of severe allergic reaction. If one comes into contact for the first time with a substance to which one is allergic then antibodies are formed against this substance. In an anaphylactic reaction the antibodies are of a particular kind. If one comes into contact with the substance in question again, the IgE antibodies … Read more


Pathological dependence on alcohol, causing mental or physical symptoms. Alcoholism usually develops imperceptibly. At first the patient drinks in the same way as those around him, then an increasing need for relaxation and increasing tolerance to alcohol make him drink larger quantities. The next stage is that alcohol is used as an intoxicant: the patient … Read more


Variation in the normal immune reaction. Immune reactions normally occur when harmful substances enter the body: antibodies are formed in the blood which render the foreign substances harmless and clear them away. Some people develop the same reaction against harmless substances, against which antibodies are formed on the first contact, without perceptible reaction, but on … Read more

altitude sickness

Condition which occurs when people who live at sea-level suddenly travel to a height of several thousand metres, caused by reduced oxygen pressure; at 5,500 metres the pressure is half that at sea-level. The condition can occur if a patient climbs above 2,000 metres, but not everyone is equally susceptible. Great physical effort increases the … Read more


Inability to remember things. Three functions are important in memory; the first is imprinting, the ability to repeat names or sets of numbers; the second is short-term memory; and important events are assigned to the third section, the long-term memory. Memory is seated in the deeper areas of the brain. Sudden temporary loss of memory … Read more


Condition in which an insoluble protein substance (amyloid) is deposited in the skin and internal organs. Symptoms are highly dependent on the place in which the amyloid is deposited; the cause, if one can be found, is usually a chronic illness such as rheumatism, osteitis, tuberculosis or a cancer. Amyloidosis of the kidneys is particularly … Read more

acute yellow atrophy

Rare liver disorder that involves massive liver cell death (necrosis) as a result of certain liver conditions, usually hepatitis. The disorder can be very vigorous, in which case hepatitis develops directly into this life-threatening condition. The condition is characterized by weakness, nausea and done, a less dangerous drug; when addicted to the latter, the user … Read more

anaemia, aplastic

Form of anaemia that results when the bone marrow produces too few blood cells, as a result of exposure to radioactivity or in rare cases through medication. The condition is often found in cancer patients because on the one hand secondary cancers may develop in the bone marrow and force out the blood-forming cells, and … Read more


Psychological and physical dependence on a drug or stimulant harmful to the user, a self-sustaining process which the addict is either unable to terminate of his own accord or can terminate only with great difficulty. The user often needs more of the substance in order to achieve the same effect (tolerance). As a result of … Read more

Anaemia, haemolytic

Anaemia caused by accelerated breakdown of red blood cells, usually because they are abnormal in form or made up of abnormal components, or because of an autoimmune disease. A particular form of haemolytic anaemia is caused by rhesus incompatibility. The symptoms of haemolytic anaemia are the same as those of anaemia in general: paleness, fatigue, … Read more

Breath, shortness of (dyspnoea)

The feeling of not getting enough air, often connected with a low level of oxygen and high level of carbon dioxide in the blood. The latter condition stimulates the respiratory centre in the brain (causing a feeling of shortness of breath), which then causes the lungs to make respiratory movements. If one deliberately holds one’s … Read more

Abdominal injury

Such injuries can have various forms, in varying degrees of seriousness, from slight to potentially fatal. They are categorized as either injuries with a visible wound (from a bullet, knife, spike on a railing etc.) or those without (caused by a kick, blow from a hard object etc.). In the latter category particularly it is … Read more

Abscess (boil)

Usually a clearly delineated accumulation of pus forming a cavity within inflamed tissue. On or near the surface of the skin an abscess is usually referred to as a boil. Pus is a fluid consisting of dead tissue, white blood corpuscles and bacteria. Whenever tissue is damaged, for whatever reason, the body reacts with inflammation … Read more


Condition of the oesophagus characterized by difficulty in moving food down the lowest part of it, caused by degeneration of the associated parasympathetic nerve cells in the oesophagus. The cardiac sphincter, which connects the oesophagus with the stomach, remains closed, and as a result food is pressed against it, causing widening of the oesophagus (mega-oesophagus). … Read more


Condition in which the stomach fails to produce hydrochloric acid, even after stimulation (with histamines or gastrins). Hydrochloric acid is important because it destroys bacteria in tissue, plays a part in the digestion of protein and affects the absorption of iron and vitamin Bl2 among other things. Despite this, a shortage does not usually have … Read more


Accumulation of acids in the body. Various chemical substances occur in body tissues, and some of them are acidic. Substances that can neutralize these acids are known as bases. For the body to function properly acids and bases need to be balanced. When excessive acidity threatens, the body loses excess acid via the lungs and … Read more


Fairly rare condition in which the acromegaly actinomycosis Infection caused by bacteria. It is fairly rare and often occurs in the mouths of otherwise healthy people. The circumstances under which bacteria cause the infection is not yet quite clear. It can occur in various parts of the body when gums are inflamed or teeth extracted, … Read more

Common Medical Terms and Their Explanations

Allergy: Abnormal reaction to otherwise harmless substances which can cause rashes, sneezing, watery eyes, asthma or swelling of lips and eyes. Commonly caused by inhaled grass pollen, but sometimes related to home dust, foods, or almost anything else. Angina: Very severe ‘crushing’ pain in the chest, caused by poor blood supply to the heart muscle. … Read more