The bones inside the buttocks, referring to the sit bones, are the parts that bear when sitting. Pain in the bones inside the buttocks may occur due to the following reasons: first, due to trauma in daily life or pain induced by a local fracture. Second, the pain is triggered by bursitis of the sciatic nodes or cysts of the sciatic bones, as well as sacroiliac arthritis or lumbar disc herniation that presses on the sciatic nerve. Third, due to the frequent sedentary in daily life, the local long-term compression, friction and then injury, and triggered the emergence of pain. After this happens, the patient should go to the hospital in time to see what kind of cause, and then give targeted treatment.