Lumbar disc herniation tailbone swelling may be related to nerve root compression or inflammation and other reasons. 1. Nerve root compression: If lumbar disc herniation occurs, the protruding nucleus pulposus will compress the nerve root and stimulate the lumbosacral or gluteal nerves, then the nerves in the lumbosacral region will be stimulated, and the middle part of the lumbosacral region will suffer from the pain, and there will be the radioactive pain, which will be radiated to the spine and caudal vertebrae, resulting in the pain in caudal vertebrae region, which will cause the distension of the sacral and caudal vertebrae. 2. Inflammation: It may also be due to other diseases caused by the attack of lumbar disc herniation, during the treatment of such diseases, it may be necessary to maintain a long period of time in the supine position, or a long period of time lying in bed and compression, etc., which may cause aseptic inflammation or pressure sores in the buttocks or the sacrococcygeal region, and then the distention of the caudal vertebrae will occur. Herniated lumbar disc and tailbone swelling may also be related to other factors, it is recommended to consult a doctor in time to identify the cause of the disease.