Low back pain after sleeping for a long time, it may be caused by the following reasons: 1, the mattress problem. If the mattress is too soft, when sleeping, the muscles of the lumbar spine must be contracted with long-term force to maintain the correct body position, there will be local long-term force resulting in strain pain. The local bed board is too hard, the local soft tissues are often compressed, and the resulting ischemic pain, will also appear lumbar pain. 2, there may be problems with lumbar spine disease, commonly lumbar muscle strain, the third lumbar transverse synovial syndrome, or lumbar disc herniation. If it is a lumbar disc herniation, the place of lumbar pain is usually in the middle of the lumbar spine, with pain in the place of the intervertebral space. If the pain is in the muscles on both sides of the lumbar spine, it is common to have lumbar strain or third lumbar transverse herniation syndrome. The lumbar spine CT or MRI can basically rule out a lumbar disc herniation.