The pain in the lower back when sleeping: 1. It may be due to incorrect sleeping posture, prolonged distortion and pressure on the lower back, which affects the local blood circulation and leads to stiffness and pain in the lower back muscles. 2. It may also be due to not covering the blanket at night and the lower back being exposed to wind and cold leading to muscle spasm and local pain. 3. The symptoms of lumbar pain can also be caused by sleeping in a soft or hard bed. So the above symptoms can be relieved by some treatments such as medication, physiotherapy, and then removing the triggers that cause the pain. If there is no relief within a short period of time, you must go to a regular hospital in time and choose a reasonable treatment method after the cause is clear.