Fever at night and fever during the day, may be infectious diseases, such as pneumonia, upper respiratory tract infections, tuberculosis, endocarditis, urinary tract infections, etc.; may also be non-infectious diseases, such as tumors, systemic lupus erythematosus and other rheumatic diseases. Fever at night, the most common in a variety of infections, such as respiratory, urinary system, endocardial and other deep infections, often accompanied by corresponding symptoms, such as respiratory infections can be coughing, coughing up sputum, shortness of breath, etc.; endocarditis patients can be due to heart failure manifested as chest tightness and shortness of breath, ultrasound can be seen in cardiac valves flabbergasted. Tuberculosis is a chronic bacterial infection, the disease is often characterized by fever in the late afternoon, continuing into the night temperature increases, may appear normal temperature during the day. Non-infectious diseases can also cause fever at night, such as tumors, systemic lupus erythematosus and other rheumatic diseases, such fever is rarely high, often with corresponding symptoms, such as lupus patients can appear rash, arthralgia, urinary protein and so on. In short, night fever during the day without fever, it is recommended that patients seek medical attention to further clarify the cause of the disease.