In Chapter IL allusion was made to the lessons taught by the duration of pain; when it was stated that its importance in cases of long-standing is to be measured by its effects, and that when of recent date, it is a symptom of but little consequence in per sons who have been long ailing, while their general health is not seriously undermined. These considerations suffice to show the necessity of inquiring into the patient's previous history, and in doing so we shall often find that the precursory symptoms, or the circumstances which have seemed to give rise to it, throw great light on its e,auses. General pain, by which is meant pain or aching not limited to particular organs, but irregularly distributed over the body, is commonly an indication of general disorder ; such as we have already studied in what are called blood-diseases, fevers, rheumatisms, even ana3mia : it may be muscular, or con fined to tla.e joints, to the bones (e. g, rheumatic periostitis), or to the nervous system, with headache and pain in the back. These varieties in its manifestation, comprising the individual elements of which the sum of general pain is composed, lead us by analysis to the various diseases and disorders in which we have already met with it as one of the symptoms. Another form of general pain is somewhat analogous in character to neuralgia ; .it is re ferred to the sensitive filaments of the nerve, but has its real seat in some portion of the cerebro-spinal axis, and is caused by dis ease of or pressure upon some portion of the central organs; it is often very irregular in its manifestation, and is of great import ance when associated, as it is sooner or later, with spasm or para lysis: occasionally it is complained of in parts which have lost some degree of their ordinary sensibility. Apart from such corroborative symptoms, there is nothing in the pain itself to distinguish its cause; when more limited in its distribution, it is apt to be confounded with neuralgia ; when diffuse and irregular, it resembles muscular rheumatism.
Local pain is either direct or sympathetic ; when accompanied by a febrile state, it is always referable to some congestion or inflammation; without fever, it is either dependent on some chronic ailment of the part, some unfitness for the performance of its ordinary functions, or it must be regarded simply as neu ralgia. The first inquiry, therefore, is whether there be any alteration in the function, normal condition, or nutrition of the part in which pain is complained of; next, whether any ailment exist elsewhere of which such pain is known to be sympathetic.
Examples of such affections are found in disorder of the liver, being fre quently associated with pain in the right shoulder ; nephralgia, especially cal culus of the kidney, causing pain in the thigh, groin, or testicle ; irritation of the bladder being referred to the meatus urinarius ; disease of the womb, leu chorrhceal and other discharges. being accompanied by pain across the sacrum ; disease of the hip-joint being often indicated by pain in the knee, &c. Some practitioners have recently attempted to substitute a theory of sympathetic or perhaps reflex pain, connected with the uterus and ovaries, for that of spinal irritation, as affording an explanation of some of the anomalous pains of hysterical females. This wants confirmation, and will in all probability be
found as baseless as the spinal irritation theory.
We must not overlook the consideration that direct pain in local inflamma tion is aggravated by movement or pressure, and is indeed sometimes only spoken of as produced by such circumstances ; bearing in mind, at the same time the exaggeration of this fact exemplified in the tenderness of hysteria.
Should careful inquiry reveal no definite cause for local pain, we must be content with the terms neuralgia and irritation ; not that they are in themselves satisfactory, but they serve to distin guish conditions beyond which we 'cannot at present penetrate. Patients generally are unacquainted with the situation and distri bution of nerves, and therefore we may fairly assume that there is more of reality and less of imagination in pain described as following the known course of some nerve, than in that which is anomalous and irregular. But while remembering that it may be the effeet of imagination, or may be simply imposture, and while all pain unaccompanied by local lesion is very liable to exaggeration, yet we know that irritation really does occur, and does give rise to pain, and therefore it must not be ignored only because we cannot find out its cause. Examples of local irrita tion are found in toothache, earache, muscular rheumatism, the effects of exercise or strain, as well as in painful digestion, pain ful menstruation, &c. An hysterical or chlorotic female has almost always pain in the left side; this is probably due to the liability to excited action of the heart, present in such cases, associated, as it commonly is with flatulent distension of the sto mach. When local irritation has a persistent character, we may conclude that there is some hidden cause for its presence.
Pain dependent on irritation is of more importance when ac companied by tenderness on pressure: so true is this, that even sympathetic pain, when severe, will produce tenderness in the part where the pain is felt, although we know certainly that the seat of the disease and the cause of the pain is located elsewhere. This observation must of course be taken with the limitation that it is not hysterical tenderness accompanying hysterical irritation.
It is sometimes quite impossible to determine the circumstances which give rise to this nervous irritation; its cause, for example, may be inseparably bound up with derangement of stomach or disorder of the intestinal canal, while its effects are really pro duced at a very distant part. When the stomach has been emp tied by vomiting, or the prim viw cleared out by a brisk pur gative, the pain immediately ceases. In such circumstances, as well as in those more usually called sympathetic, there is probably something of a reflex action ; and to them the name of neuralgia might with some propriety be applied ; it seems better, however, to confine it to cases in which there is some actual impression on the nerve-trunk, producing sensations in the branches. Though not limited to any particular nerves, there are a few in which it is more commonly met with than in others, and to them distinct names have been applied.