Low back pain from 3am to 5am may be caused by cold, improper sleeping position at night, herniated lumbar disc and so on. 1. Cold: not paying attention to keep warm at night rest, resulting in the waist wind and cold, appear in the early morning back pain. 2. Improper sleeping position at night: If the sleeping position at night is incorrect, or the hardness of the mattress is not suitable, or keep the same position for a long time, resulting in back pain. 3. Lumbar disc herniation: patients with lumbar disc herniation, sleep at night, because the mattress is too soft, the waist is not supported, can also lead to localized pain in the middle of the night. There are many reasons for back pain from 3:00 to 5:00 a.m. It is recommended that patients be admitted to the hospital in a timely manner, to clarify the cause of the disease and treatment to avoid further aggravation of the condition.