FEVER (Lat. febris, from ferveo, I grow warm, or perhaps from februo, I cleanse), a form of disease characterized principally by increase of the temperature of the body, which, however, requires to be estimated according to the state of the internal parts, rather than the external; the surface of the body, and particularly of the extremities, being not unfrequently cold rather than warm. Having regard to the heat of the surface only, F. has commonly been considered as passing through three distinct stages, more or less marked: 1, the cold or shivering stage; 2, the hot stage; 3, the sweating stage. This description is perfectly correct in most cases, but it requires to be qualified by the remark, that even in the cold stage of fevers, it is now well ascertained that the blood and the internal organs have an elevated temperature, as estimated by the thermometer introduced into the cavities of the body. In the cold stage of F., accordingly, and even in the most violent ague, when the teeth are chattering with cold, and the whole surface is pale and clammy, the state of the system is well expressed by the aphorism of Virchow (the most ingenious and comprehensive of the modern exponents of the pathology of F.), to the effect that " the outer parts freeze while the inner burn." Increased heat of the body, therefore, is the most essential, perhaps the only essential phenomenon of fever. The other symptoms are loss of appetite, thirst, restlessness, and vague general uneasiness, often headache, and diffused pains in the back and limbs; a frequent pulse, which is sometimes also full and hard; a furred tongue, often with red margin; a flushed face and suffused eyes; vitiated secretions, and general derangement of the functions, with great debility of the voluntary movements of the limbs. The disease often commences with a shivering, or rigor, as it is technically called; this leads through the cold stage to the hot, which usually follows pretty rapidly, and is attended by all the febrile phenomena in their highest degree; the skin being often very pun gently warm to the hand, dry, and harsh; by and by, the pores appear to open, moisture begins to bedew tile surface, and the pungent heat disappears: the disease is then about to pass into its third or sweating stage, which ushers in the convalescence. For the special
symptoms of particular fevers, see TYPHUS and TYPHOID FEVERS, SMALL-PDX, Senn LET FEVER, MEASLES, AGUE, INTERMITTENT and REMITTENT FEVER, YELLOW FEVER.
Besides being thus the leading fact in a number of specific diseases, F. is also asso ciated with many other forms of disease as a secondary or subordinate phenomenon. connected with an inflammation or other distinctly ideal disease. Thus, in pneumonia (q.v.) or enteritis (q.v.), F. is as much a part of the symptoms as pain or any other; and even in some chronic or long-standing diseases, as in consumption (q.v.), a slow and consuming type of F. (see HECTIC FEVER) is found to be very generally present. Indeed,. there is no condition which rules so large a part of the physician's duty, whether in the way of distinguishing diseases or of curing them, as this constitutional state. F. is also very generally prevalent after surgical operations and injuries, of which it constitutes one of the leading "dangers; and in midwifery practice, it is well known7iis constituting a large part of the risks of the puerperal state, Whtther in the slighter form commonly called a weed, or in the more dreaded and fatal, often epidemic, form of puerperal fever (q.v.) The family of fevers is thus separated pretty naturally into two large groups, in one of which the F. is the greatly predominating fact, and determines the specific cha racter of the disease; the local disease (if present) being quite subordinate, and usually secondary in point of time; the other, where the opposite order prevails, and the F. is obviously secondary. Hence the distinction embodied in medical language between allopathic (i.e., self-originating, spontaneous), and symptomatic or fevers. Fevers are also distinguished, with reference to their mode of diffusion, as epidemic (q.v.) and endemic (q.v,); or with reference to their supposed cause, as contagious, infec tious, malarious, pneumonic, rheumatic, etc. ; or with reference to their incidental symp toms and their peculiarities of course and termination (the presumed specific phenomena attracting, of course, particular attention), as eruptive (see EXASTIIEMATA) or non eruptive, bilious, gastric, enteric, mucous, putrid, malignant, typhoid, etc.