If the fever subsides on its own, there are the following reasons: 1. When bacteria, viruses and other pathogenic microorganisms invade the body, if the patient has a fever because of a cold, it has a certain self-healing period and self-healing function. The human body has a certain self-defense function and self-immune function, in the case of normal immunity, the fever can subside by itself in about 7 days. 2, if the patient with good immunity is infected, the infection is not particularly serious, but also due to the activation of the endogenous antigen-antibody complexes so that the fever will subside by itself. 3, if the fever is well recuperated, or a large amount of water, pay attention to warmth, bed rest, immune function and immune barrier is more normal, the fever will subside by itself, and the immune function and immune barrier is more normal. When the immune function and immune barrier are normal, spontaneous healing may also occur.