Five o’clock in the morning back pain may be caused by poor sleeping posture, lumbar muscle strain, urinary stones. 1. Poor sleeping posture: If the sleeping posture is not correct, or if keeping a posture for a long time will cause back pain, then you can choose to sleep on a hard board bed or a soft pillow under the waist. 2. Lumbar muscle strain: patients with lumbar muscle strain may have strong pain in the morning, which is due to the spasm of the lumbar muscles during sleep, thus exacerbating the pain. 3. urinary stones: this is because the stones block the urethra, the ureter may be caused by dilatation, as well as fluid in the kidneys caused by back pain. Five o’clock in the morning back pain may also be seen in the lumbar disc herniation, nephritis and other diseases, if the symptoms of five o’clock in the morning back pain, persistent and unrelieved, the need for timely medical treatment.