The fluctuation range of low fever temperature is 37.3℃-38℃. If you have low fever every afternoon, you need to pay attention to exclude the following diseases: First, consider tuberculosis, which is a chronic infectious disease seen in several organs of the body, but the most common is pulmonary tuberculosis. In addition to low fever in the afternoon, it is accompanied by night sweats, cough, sputum, hemoptysis and other symptoms, it is recommended to do chest X-ray and lung CT to find lung lesions, and at the same time Tuberculosis antibody tests, repeated sputum tests for tuberculosis bacteria, fiberoptic bronchoscopy and Tspot examination are needed to exclude tuberculosis if necessary. Second, other infectious and non-infectious fevers should be considered. Infectious fevers include urinary tract infections, biliary tract infections, and gastrointestinal tract infections, and non-infectious fevers include rheumatic immune system diseases and tumors, which can also cause fever.