Recurrent high fevers can be associated with a variety of factors and are commonly associated with infectious as well as non-infectious diseases. In addition, when there is an allergic reaction, the phenomenon of recurrent high fever may also occur. 1. Infectious diseases: common infectious diseases include influenza, acute tonsillitis, acute mastitis, acute cystitis, pneumonia, encephalitis and so on. When the body is invaded by viruses or bacteria without effective control, high fever will not go down. After diagnosis, we can actively anti-infective treatment for the corresponding pathogens, which can alleviate the symptoms of fever. 2. Non-infectious diseases: Non-infectious diseases such as leukemia, malignant lymphoma, etc. will also cause patients to have recurrent high fever, which may be accompanied by symptoms such as fatigue and emaciation, and can be life-threatening in serious cases. After diagnosis, the tumor should be treated accordingly. 3. Metabolic reaction: for example, allergic reaction after vaccination or metabolic reaction caused by blood transfusion or fluid transfusion will make the patient suffer from recurrent high fever that does not go down, which is more serious and needs to be dealt with immediately. There are other diseases that can lead to recurrent high fever, such as recurrent high fever, you should consult a doctor as soon as possible for examination, to clarify the causes of high fever, under the guidance of the doctor for reasonable treatment, do not use your own arbitrary drugs, so as not to delay the condition.