DLTRATION AND SEQUENCE OP PHENOMENA.
THE inquiry into the first manifestation of any deviation from health, the duration of the disease, and the order and sequence of the phenomena, is of considerable importance, as defining in gene ral terms not only the whole period of the illness, but also, in some measure, the continuance of each particular derangement, and establishing a certain relation between each- new symptom and that which immediately preceded it.
From the preliminary inquiry as to the age, occupation, and habits of the patient, valuable suggestions are sometimes obtained. We need not dwell upon the variations in the character of dis eases, as they occur in infancy, youth, adult life, and old age, because these are rather associated with stages of development than with periods of years ; but we may refer to the information of tardy growth or premature decay, which the contrast between the actual and the probable age of the individual sometimes re veals ; and to the liability at certain ages .to the occurrence of specific diseases. In a still more marked rummer does the occu pation of the patient become the direct index of the disease under which he is laboring, as we know that in the pursuit of certain trades men are necessarily exposed to the influence of various morbid agencies. Nor less important is a knowledge of previous habits in enabling us to calculate the strength of constitution, or the tendency to unhealthy action, in warning W3 that certain modes of treatment must or must not be adopted, and in pointing out the diseases which will be the probable consequence of baneful in dulgences.
1. Duration divides diseases into acute or rapid, and chronic or slow.
2. It sometimes tells of a previous condition of weakness and long ailment, which, though it does not negative the subsequent occurrence of acute disease, guards against a hasty decision, and is of immense value in determining on tre,atment.
3. It gives a measure of the intensity of pain and suffering, by enabling us to compare its effect on the patient's health, with its alleged duration.
4. The order of sequence helps us in tracing back the pheno mena of disease to their origin, while the first deviation from health sometimes points at once to the organ affected.
5. It sometimes enables us to exclude certain possible diseases to which the symptoms might lead, by the knowledge that in their course events occur at fixed periods, which may have been already passed by.
1. The question whether a disease be acute or chronic is not one merely of intensity. The clinical history, the pathological changes, and the treatment, are all of them often very different, not only in degree, but also in kind. Little is known of the essence of disease ; and when similar causes give rise to some what similar groups of symptoms, we are content to assume a similarity in the disease. This we do even when in detail it may be very difficult to point out an exact resemblance between any of the particulars in two cases bearing the same name, of which the one has been of long duration and minor inten sity, while the other has been of shorter duration and greater intensity. The name is merely the mark or sign by which we agree to distinguish the group of symptoms ; and its relation to other similar groups is conveyed by the resemblance of their denomination. But the inquiry has a further applica tion; for, inasmuch as the existing phenomena may be produced by one of two causes, of which one develops its effects in more rapid succession than the other, the duration of the disease will often aid in determining to which of the two they are to be referred.
2. Long ailment may imply either a peculiar susceptibility in the constitu tion of the patient which exaggerates minor sufferings, or an actual depression of the vital powers, from protracted illness. In each case, evidence of a re cent severe attack must be unquestionable before we give our assent to the existence of acute disease ; in the one, because the susceptibility of the patient so greatly influences the character of the symptoms; in the other, because the depression of the vital powers renders the supervention of active disease more improbable, and stamps it with a character different from that which it has in a healthy individual. In both cases, bearing in mind the subservience of diagnosis to treatment, the information is most valuable in directing the selection of remedies. .