Lying down back pain can be caused by the following reasons: first, dorsal myofasciitis, dorsal myofasciitis can have lying down back pain symptoms, often due to back cold, exertion and lead to, can be accompanied by morning pain aggravation, after a while in the activities can be improved. At this time, it is necessary to check and examine the body early to exclude other diseases for diagnosis; second, rheumatoid, when rheumatoid involves the spine, it can have the symptom of back pain after lying down, which can be accompanied by morning stiffness, and then it is necessary to check the blood test as well as shoot the X-ray film of the spine, and CT to diagnose it; third, osteoporosis of the spine, when the spine is seriously osteoporosis, it can have the symptom of back pain after lying down. At this time, blood tests, CT and MRI of the spine should be taken for diagnosis; fourth, tumor of the spine, when there is a tumor in the spine, there can be symptoms of back pain after lying down. In this case, MRI and CT of the spine should be examined to diagnose the tumor, and blood tests should be done to assist the diagnosis if necessary.