The causes of fever at 5 p.m. every day are various, including infectious diseases, rheumatic diseases, malignant tumors and so on. 1. Infectious diseases are most common in tuberculosis, but also in brucellosis and typhoid fever. Fever at 5 pm every day, if accompanied by night sweats, fatigue, emaciation symptoms, should be highly suspected of tuberculosis, suggest that the patient as soon as possible to the hospital for blood routine, tuberculosis culture examination, as soon as possible to determine the cause of the disease. 2. Rheumatic diseases can cause fever, also can appear in the afternoon fever obvious phenomenon. 3. In addition, hematologic diseases such as acute leukemia, malignant lymphoma, malignant histiocytosis, and malignant tumors can also appear in the afternoon around 5:00 p.m. to start the fever phenomenon. There may be other reasons for afternoon fever, you should seek medical advice in time, go to the hospital under the guidance of the doctor for examination, to clarify the cause of the disease and then treat the cause of the disease.