Back stiffness and pain after getting up in the morning may be caused by the following reasons: First, it may be that when sleeping, the mattress is too soft or the bed board is too hard, resulting in the muscles of the back having to exert themselves for a long time when sleeping to maintain the position of the thoracic or lumbar spine, resulting in long-term muscle contraction spasm, resulting in back stiffness and pain. Second, it may be that when sleeping, the back accidentally caught a cold, resulting in the back muscles after the cold, poor blood circulation, or cold muscle spasm, resulting in stiffness and pain. Third, diseases of the muscles of the back, such as myofasciitis of the back or misalignment of the small joints of the thoracic spine. In the case of myofasciitis of the back, the muscles on both sides of the back will usually be painful; in the case of misalignment of the small joints of the thoracic spine, the painful areas are mainly pressure pain in the middle intervertebral space of the thoracic spine, accompanied by limited movement of the thoracic spine.