After falling on the buttocks, you should seek medical treatment promptly, and the specialist will clarify whether a fracture has occurred based on the symptoms and signs, and auxiliary examinations. 1. Symptoms and signs: After falling on the buttocks, check the lumbar and sacrococcygeal area, thigh root area and groin area for symptoms and manifestations such as pressure pain, swelling, deformity, subcutaneous petechiae, bruising, etc. At the same time, observe the local activities to see if there is any limitation of functional activities. 2. Auxiliary examination: X-ray, CT and other imaging examinations should be carried out under the guidance of doctors to observe whether there is any interruption of the continuity of the bone cortex, whether there is any fracture of the bone trabeculae, and whether there is any displacement, angulation, separation, insertion and other manifestations. In order to rule out fracture after falling on the buttocks, one should consult a doctor in time and improve the examination, and should not judge on one’s own purely from the symptoms and so on.