Neuralgia is a painful affection of nerves, the pain being distinguished by the fact that it is sharp or knife-like in character, and occurs in regular twinges. Women are more frequently attacked than men, and neuralgia is very largely a disease of debility, indicating, as it does, that the nervous system is run down. It very often occurs, for example, in association with anaemia, or after any acute illness such as influenza.

Chill may bring on an attack, and it sometimes occurs in such diseases as rheumatism, gout, and diabetes, due to irritation of the nerves by the special poison of the disease. On the other hand, neuralgia may be due to some simple local cause, such as a decayed tooth or a little tumour of bone, whilst a gland may press upon the nerve. Lastly, any unhygienic condition tending to lower the general health, such as over-fatigue, worry, poor food, or ill-ventilated homes, will predispose to neuralgia.

There are various varieties of neuralgia, depending upon what nerves are affected. For example, facial neuralgia, called sometimes tic douloureux, is characterised by severe pain in the nerves over the face, affecting sometimes the eye, and sometimes the region of the ear and jaw. The next important form of neuralgia is called intercostal neuralgia, affecting the nerves supplying the muscles of the chest. It is often mistaken for pleurisy, and may be accompanied by herpes, or eruption of the skin, along the course of the nerves. Another form of neuralgia is "painful heel," which occurs without any apparent cause, so severely sometimes as to interfere with walking. The neuralgic pain may be found in the nerves of the sole of the foot or at the tips of the toes.

In the treatment of neuralgia it is not of the least use to deal with the pain in itself without finding out the cause. Even if the pain is removed for the time being it will certainly recur until the general health is improved, and any cause of irritation removed. In neuralgia of the face the teeth should be carefully examined, each one pressed upon separately, and a dentist should see to the stopping of any holes and the removal of any stumps.

If anaemia exists, it must be treated with iron tonics and other measures. Nutrition should be improved by good food, plenty of fresh air, and exercise out of doors. In the case of gout or rheumatism, careful diet and strict limitation of flesh foods will sometimes cure the neuralgia altogether. The best medicines are fresh air and change of air. The outdoor life is the most useful measure very often in removing a long-standing neuralgia. Medical tonics may be necessary, but these should be prescribed by a doctor, as they must be given carefully if the nervous system is not to be exhausted still further. Milk, cream, and cod-liver oil may be taken liberally to improve the general nutrition, and plenty of sleep is one of the best measures. This is one of the affections where people must be particularly careful not to get into the habit of drugging the pain. A very large percentage of cases of morphia habit, for example, have originated in neuralgia when sedative drugs were taken to soothe the pain. Heat is one of the best domestic measures. Hot flannels, hot and cold bags, poultices, or roasted cotton-wool will soothe the pain and often remove it for the time being. Then there are various liniments of belladonna and chloroform, which are very useful. In neuralgia of the face, for instance, the plaster should be placed behind the ear. Electrical treatment is often very successful. It should be applied by a properly qualified person.

Neurasthenia is a general weakness or exhaustion of the whole nervous system, giving rise to a great variety of symptoms. It is very often associated with overstrain, either physical or mental, and it seems to have become much commoner of late years, especially among business and professional men, teachers, writers, stockbrokers, and those who are exposed to constant strain in daily life. It may develop after a sharp illness which has lowered the resisting power, and one of the early symptoms is the tendency to worry over non-essentials, to be easily annoyed, irritable, hurried, and subject to headache and depression. Neurasthenia is only hereditary in the sense that the offspring of parents who have been subject to nervous or mental complaints, who have led unhealthy lives and spent extravagantly their nervous energy, start life handicapped by a nervous system ill-fitted to withstand strain. They have no reserve of nervous energy, and although they can stand an ordinary amount of strain and work, they are apt to break down if this strain is at all excessive.

The subject of "nerves" has been considered in a series of general articles in the Encyclo-paedia, and much that was said then applies to neurasthenia, because so-called "nerves" is simply this disease in its early stage. After a time, without proper treatment and care, the nervy person degenerates into the neurasthenic, whose aches and pains may be referred to every organ or system in the body. The patient may complain of heart symptoms, stomach symptoms, spinal or head pains. Insomnia is nearly always present, whilst the mental symptoms are the most depressing of all. The neurasthenic finds it difficult to fix the attention, to concentrate on work. It may cause him most acute worry to write or dictate a letter, to add up figures, or to make arrangements about the most ordinary affairs of everyday life.

These patients are often very difficult people to get on with. They "feel misunderstood, neglected, and are often selfish and egotistical to a degree. In many instances their state of mind is pathetic. They are constantly worried and anxious, possessed by various fears. They may fear sudden death, for example, or insanity. They often shun society to a morbid degree, or are unable to cross an open space or look down from any height. They are subject to all sorts of aches, one of the commonest being constant pressure or pain in the head, and the slightest exertion or effort causes exhaustion. In many instances the symptoms are very vague, but in every case there is depression of mind, physical and nervous weakness and anxiety. Fortunately, however, neurasthenia is a curable disease even when it has lasted for some time.