Low back pain is a symptom, not an independent disease. There are many causes of low back pain, the majority of which are known, but there are still a few causes that have not yet been identified. The common causes can be summarized into four major categories: (1) caused by disorders of the spinal bones and joints and their surrounding soft tissues. Such as contusions, sprains caused by local injury, bleeding, edema, adhesions and muscle spasm. (2) Caused by spinal cord and spinal nerve disorders. Such as back pain caused by spinal cord tumor, myelitis, etc. (3) Caused by disorders of internal organs. For example, infections and tumors of the uterus and its adnexa can cause lumbosacral pain, and such patients are often accompanied by corresponding gynecological symptoms. (4) Caused by mental factors. For example, patients with hysteria may also complain of lumbar disease, but there are no objective signs, or the objective examination and subjective narrative cannot be explained by knowledge of physiological anatomy and pathology, and such lumbar pain is often a manifestation of hysteria.