This situation occurs, to consider non-disease causes, disease causes, etc., as follows: First, non-disease causes: the bed chosen is not suitable, such as sleeping on a very soft bed, this time the spine will be sunken, especially the thoracic spine, the physiological curvature of the thoracic spine changes, which will lead to higher muscle tension in the back, which will cause strain on the back muscles, therefore, in the middle of the night will lead to pain because of muscle strain aggravated. Second, the cause of disease: consider ankylosing spondylitis, ankylosing spondylitis is typically manifested by back pain and lumbar pain at night, and the pain can be relieved in the morning by moving the joints of the lower back in the morning. In this case, a blood HLA-B27 test should be performed, as well as a lumbar spine film and bilateral sacroiliac biphasic x-ray to clarify the diagnosis.