The pain in the middle bone of the buttocks when sitting down is very likely due to a bone lesion, such as osteophytes, osteonecrosis, fractures, etc. This situation is actually more serious, it is recommended to go to the hospital for examination in a timely manner, you can take an X-ray examination, CT examination or MRI examination to clarify the situation, and then choose the appropriate method for treatment. In addition, bone pain does not mean that the bones are diseased, it may also be caused by a lesion in the lumbar spine and compression of the bones in the middle of the buttocks, which proves that the situation in the lumbar spine is more serious and needs to be treated as soon as possible, otherwise there may be more serious consequences. No matter what kind of pain is caused, patients should go to the hospital in time for examination and do some related treatment.