The following reasons may cause pain and numbness in the back: 1. If the pain and numbness are located in the back of the shoulders, it is likely to be caused by cervical spondylosis. Cervical spondylosis refers to a series of symptoms caused by bony growths in the cervical spine that compress the cervical nerves, cervical blood vessels, or cervical spinal cord. If cervical spine growths compress the cervical nerves, especially the sixth and seventh cervical vertebrae, the nerves of these two cervical vertebrae are distributed in the back of the shoulder. If these two cervical nerves are compressed, pain and numbness will occur in the upper third of the back, which is the most common cause of numbness and pain at the same time.2. If the pain and numbness are in the middle and lower part of the back, it is very likely that it is due to intercostal nerve injury that triggers the symptoms. Whether it is the lateral curvature of the thoracic spine, or the disorder or hyperplasia of the small joints of the thoracic spine can compress the intercostal nerve. If the intercostal nerve is compressed for a long time, pain and numbness in the back will occur, but most of the pain will be on one side of the back.