Apyrexia

APYREXIA (from Greek a- negation, and pyr-fire), a period of fever when the feverish temperature has fallen to normal and sometimes even below normal. Although the most important symptom of fever—the elevation of temperature—is absent in the apyretic stage, the febrile process itself is not yet finished. Only gradually does the organism recover from the disturbances of metabolism and intoxication caused by the causative agent of the fever (pyrogenic agent). The onset of apyrexia is often accompanied by the onset of general weakness of the organism (sometimes collapse), profuse sweating, and dilation of the skin vessels. In the further course, increased diuresis, intensified oxidative processes in the organism, and processes of chemical regeneration in the cells restore the biochemical and physicochemical normality of cellular elements and intercellular substances. Apyrexia may again be replaced by an increase in temperature, as is usually observed in malaria and relapsing fever (see Fever).