Adults with fever at night and normal during the day are commonly seen in infectious fever, such as bacterial, viral, fungal infections, etc.; they are also seen in non-infectious fever, such as hyperthyroidism, immune diseases, etc. 1. Infectious fever: such as bacteria, tuberculosis caused by Mycobacterium tuberculosis, most of the fever at night, normal during the day, accompanied by fatigue, lethargy, etc., need to go to the hospital, the DR film examination. Also seen in viral infections, fungal infections, the body’s resistance is weaker at night, easy to fever. This time to the hospital to check the cause of fever, necessary oral antipyretic drugs, such as ibuprofen. 2. Non-infectious fever: such as hyperthyroidism, rheumatic immune disease, etc. Some tumor patients can also have fever at night. Adults with fever at night and normal during the day need to go to the hospital for timely examination to clarify the cause of the disease.