Sunken buttocks may be caused by congenital developmental abnormality, lumbar disc herniation, hip joint occupational lesion and other factors. 1. Congenital developmental abnormality: due to congenital individual differences, in the process of development, the structure of the buttocks is abnormal, which will lead to visual depression on both sides of the buttocks, usually there are no other clinical symptoms, and there is no need for special treatment. 2. Injury: both sides of the buttocks have suffered injuries, such as burns or falls, resulting in local soft tissue damage, local deformities, changes in the shape of the buttocks, which will make the buttocks sunken on both sides. 3. Lumbar disc herniation: may be related to acute injury, lumbar degenerative changes and other factors, as the nerve will be compressed by the disc, may lead to gradual atrophy of muscles in the innervated area, will lead to the buttocks on both sides of the depression. Hollowing on both sides of the buttocks and the presence of other abnormal manifestations should be alerted to disease factors, and it is recommended to consult a doctor for examination and treatment.