Pain in the spine below the cervical spine often suggests the presence of thoracic spine-related lesions in patients, and the common causes of such lesions are mainly as follows: 1. Misalignment of the small joints of the thoracic spine may occur. The thoracic spine here often produces small joint misalignments in the intervertebral joints due to its shape and structure. Once the relationship between the intervertebral joints is disturbed, it will easily lead to pain here. 2. It may be caused by damage to the ligaments associated with the thoracic spine. For example, the intense activity of the patient causes strain on the supraspinous ligament and interspinous ligament of the thoracic spine, which will cause pain here. 3. It may be caused by the protrusion of the thoracic intervertebral disc. The thoracic spine has a narrow spinal canal, and once the thoracic disc is herniated, it can easily lead to significant pain in or around the thoracic spine. 4. It may be caused by a fracture of the thoracic spine. Fractures in the thoracic spine can be traumatic fractures caused by strenuous activities or falls, or pathological fractures caused by osteoporosis in patients. Either way, it can cause significant pain in this area. Finally, the pain in this area may also be caused by the patient developing severe osteoporosis.