The underlying cause of hunchback is longitudinal asymmetrical growth in the anterior or lateral front caused by various factors, which causes one or several segments of the spine to curve to the side, creating a spinal deformity with curvature in the thoracic back. Common causes of hunchback include ankylosing spondylitis, bone fracture and congenital spinal dysplasia. 1. Ankylosing spondylitis: it is a rheumatoid immune system disease, the specific cause is not clear, it is generally believed to be caused by genetic factors and infectious factors, immune factors, endocrine factors and other factors. Typical manifestations are dull pain and morning stiffness in the lower back, aggravated by rest and alleviated by activities. With the progress of the disease, the spine will gradually deform, ankylosis, and even disability. 2. Fracture: mostly caused by indirect external force, when falling from a high place and landing on the hip or foot, the impact external force is transmitted upward to the thoracolumbar segment, and fracture occurs, which shows symptoms such as localized pain, activity limitation, deformity, and compression pain. 3. Congenital spinal dysplasia: It is due to abnormal changes in the formation and growth of bones during fetal period, resulting in scoliosis and showing the symptoms of hunchback. In addition to the common causes mentioned above, there are some other causes that can also lead to the symptoms, such as spinal tuberculosis, vertebral tumors, vitamin D deficiency, etc. It is recommended to seek medical treatment in time to avoid worsening the condition.