Buttock pain and leg pain may be caused by lumbar spine disease, pyriformis syndrome and sciatic nerve disease. 1. Lumbar spine disease: due to lumbar degeneration and trauma caused by lumbar disc herniation, lumbar spinal stenosis and lumbar spine fracture and other diseases that lead to nerve root irritation and compression, the patient may appear in the buttocks and lower limbs, pain, numbness, and activity limitation and other symptoms. 2. Piriformis syndrome: due to injury, edema, inflammation of the piriformis muscle, resulting in sciatic nerve compression, patients may experience pain in the buttocks and legs. 3. Sciatic nerve diseases: such as sciatic neuritis, sciatic nerve tumor and other diseases cause pain in the sciatic nerve innervated area such as buttocks and lower limbs. Buttock pain and leg pain may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.