Body fever in the early morning may be caused by infections, autonomic dysfunction, tumors, tuberculosis, immune system and other diseases. 1. Infections: Infections include viral infections, bacterial infections, mycoplasma, chlamydia infections, parasitic infections and so on. Disease-causing microorganisms enter the human body, leading to an upward shift of the thermoregulation point, which can cause fever. 2. Autonomic nerve function disorder: the fever in the early morning is considered to be related to the usual mental tension, excessive stress in life, work and study, which leads to autonomic nerve function disorder and fever. 3. Tumor: Tumor patients have low resistance, which can easily induce infection and cause fever; the use of chemotherapeutic drugs may cause drug fever; the growth of cancer cells in tumor tissues is faster, the blood supply is not good and necrosis and absorption occurs, and the process of absorption of the body causes fever, which leads to fever in the early hours of the morning. 4. Tuberculosis: due to the existence of tuberculosis poisoning symptoms, patients with tuberculosis may cause low fever, mainly in the middle of the night and afternoon fever. 5. Immune system diseases: immune system diseases such as dermatomyositis, systemic lupus erythematosus, rheumatoid arthritis, etc., may cause significant inflammatory response, resulting in early morning fever. Body fever in the early hours of the morning, it is recommended to pay attention to the temperature changes in the armpits to find out whether the body temperature is elevated. If necessary, go to the hospital vomiting internal medicine, respiratory medicine, to clarify the causes of fever in the middle of the night, for the treatment of the primary disease.