Sleeping flat on your back with pain in your buttocks and tail on your side without pain changing mattresses, applying hot compresses, changing positions, oral NSAIDs, braking, and so on. Choose the appropriate therapy according to the specific cause of the disease. Common causes are physiological factors, lumbar disc herniation, tailbone injury, etc.. 1. Physiological factors: If the bed is too hard to lie flat, a large area of stimulation of the tailbone, soft tissue congestion, swelling, there will be a flat tail pain, while the side of the force surface is reduced, will not be painful. There is no need for special treatment, replacement of soft mattresses, localized hot compresses can relieve pain. 2. Lumbar disc herniation: patients with lumbar disc herniation, long-term nerve compression, it will cause lumbosacral pain, radiating to the tailbone, can be seen lying down to sleep on the buttocks tail pain side pain. Oral non-steroidal anti-inflammatory drugs such as ibuprofen can be taken to relieve pain. 3. Tailbone injury: trauma caused by tailbone injury, will lead to muscle and soft tissue congestion, edema, accompanied by tailbone pain, and then lying down to sleep buttocks tail pain side pain, should be local braking, local hot compresses on the swollen parts, change the position, the pain is serious, oral non-steroidal anti-inflammatory drugs, such as diclofenac sodium delayed-release tablets, and so on. Lying down to sleep ass tail pain side 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, give targeted treatment or treatment. All of the above drugs need to be used under the guidance of a doctor.