Anxiety is a normal part of everyday life and we could not live without a degree of protective anxiousness while, say, driving a car or watching over children at play. We also find in anxiety some of the energy to do well in business or other activities. It does, however, become an illness if It lasts longer than the situation warrants and interferes markedly with our daily life and nightly sleep.

Anxiety is an unpleasant feeling characterized by fear, persistent dread, apprehension and uncertainty. The sufferer may be unaware of any cause and often believes that the cause is physical but, in spite of physical symptoms, it is a disorder of the emotions persons suffering from anxiety alone differ from those with depressive illness because of the absence of pessimism, sadness, hopelessness and possibly despair.

An extreme example of an anxiety state is separation anxiety which occurs in infants who are separated from their mothers for a considerable time. At first the child is tearful, anxious and irritable, then becomes quiet, detached and almost emotionally unreachable. The child also fails to progress physically. Happily, if mother and child are united within, say, three months, the child are usually reverts to normality, although there is a possibility of psychological scarring.

There are many psychological theories about the causes of anxiety. Some hold that its origins are to be found in the sexual life and feelings of the individual, others that it is based on a person's need for power, to be someone. Another says that it is really a beneficial mechanism - nature's attempt to heal and someone else has said, very simply, that anxiety is fear spread out thin. Therefore, anxiety states may arise from all sorts of conflicts between the individual's needs and reality, and emotions play a leading part.

The sufferer may complain of a wide variety of symptoms: vague fears, pointless apprehension and very often an explicit feeling of panic. Palpitations (being aware of the heartbeat) are common, with giddiness, flushing, sweating, diarrhoea, headache and weariness. Indigestion and vague pains of various types can appear and the mouth may be dry. Impotence and premature ejaculation in men and vaginismus (painful contraction of the vagina during sexual intercourse) in women are often revealed on examination.

Sleeplessness, uncomfortable dreams, often nightmares, and a feeling of fatigue on awakening are very common findings. It is often difficult to concentrate and there is frequently an alarming fear of going mad.

When anxiety arises, it tends at first to be spread out widely and freely, touching most aspects of a person's life. Continued anxiety may result in distressing and disabling panic attacks. The word 'panic' comes from the name of the Greek god, Pan, who would lurk in the forest and reduce travellers to a state of 'panic' by terrorizing them. These attacks tend to occur when another strain is suddenly added to the tension state. Panic is a most unpleasant experience, characterized by extreme fear, and it can lead to the developing of particular fears or phobias, the commonest being fear of open spaces (agoraphobia) or closed spaces (claustrophobia). Aeroplane, bus or train travel and using lifts may all provide problems. If unable to avoid a situation he fears, the sufferer is thrown into a panic, often accompanied by a great fear of collapse.