Recurrent fever, most commonly associated with viral colds, may last from 3 to 5 days, or even a week. In addition to this it is also common to see meningitis, lung infections, tonsillitis, sepsis, etc. There are various causes of recurrent high fever. Viral upper respiratory tract infections are often sudden high fever accompanied by cough, shortness of breath, sore throat, etc. Some viral infections of the digestive system can lead to prolonged diarrhea, which can also be accompanied by recurrent fever; and some infections of the urinary system, such as nephritis in the acute phase, can also cause recurrent fever. Patients with immune system diseases, such as AIDS, may also have prolonged fever of unknown origin, accompanied by loss of appetite, weight loss, and swollen lymph nodes. Non-infectious diseases can also cause persistent high fever, such as intracranial injury and grand mal seizures, and some malignant tumors can also cause persistent fever, such as leukemia. If fever occurs repeatedly or is not effective after using antipyretic drugs, you should promptly go to the hospital for examination and clear diagnosis. In conclusion, the occurrence of recurrent fever must be taken seriously enough. Because repeated fever can damage the function of important organs such as heart, brain, liver and kidney. First of all, you should go to the hospital in time to clarify the cause of the disease and treat it for the cause. Second, you should pay attention to rest, drink more water, take some physical cooling methods to reduce fever, and when it is not effective, you can take oral antipyretic drugs.