Fever is caused by dysfunction of the body’s thermoregulatory center under the action of pyrogenic sources, and the body temperature exceeds the range of about 36℃~37℃, which is manifested as an increase in body temperature, caused by various types of microbial pathogens, or caused by leukocyte pyrogenic sources. 1, there are bacterial, viral infection caused by fever, such as pneumonia, tonsillitis, tuberculosis, appendicitis, colds, mumps, hepatitis, AIDS, etc., need anti-bacterial, anti-viral infection treatment, can be detected by laboratory tests. 2.Fever caused by parasites, such as malaria, etc. 3.Fever caused by physical factors and chemical factors. Fever caused by injury, heat stroke, wind chill, surgery or trauma, etc. belong to fever caused by physical factors. Dehydration, acidosis, drug poisoning, etc. belong to the fever caused by chemical factors. There are also 4, central fever, such as brain hemorrhage, brain tumor, cerebral infarction, etc. 5. Fever caused by bad mood, such as overthinking, which leads to spleen damage, can also cause fever. When you encounter fever, you should generally look for the corresponding part of the onset of fever according to the fever type and the accompanying symptoms, determine what causes the fever, and instead carry out targeted treatment, pay attention to drink more water and avoid straining.