There are many causes of back pain after waking up, such as excessive exercise and other physiological factors, as well as lumbar back myofasciitis, lumbar intervertebral disc herniation, ankylosing spondylitis and other pathologic factors. 1. Excessive exercise: Excessive exertion and exercise during the day and during sleep may lead to the production of large amounts of lactic acid in the muscles, and the accumulation of lactic acid in the local area, which will cause low back pain after waking up the next day. 2. Lumbar back myofasciitis: such as prolonged overexertion, desk work, cold and other factors, can cause aseptic inflammation of the muscles and fascia of the lumbar back and other tissues, resulting in lumbar back pain and restricted movement. 3. Herniated lumbar intervertebral disc: Herniated lumbar intervertebral disc, due to the degeneration and protrusion of the intervertebral disc, causing local tissues and nerve roots to be stimulated, causing pain, numbness and other symptoms of the lumbar back, and in severe cases, it will also cause radiating pain in the lower limbs. 4. Ankylosing spondylitis: it is a rheumatic disease that mainly involves the sacroiliac joints at first, and with the progress of the disease, it can gradually involve the whole spine, which is mainly manifested as pain and morning stiffness in the lower back. There are many other causes of back pain after getting up, such as trauma, urinary system diseases, etc. If you do not relieve after resting, it is recommended to go to the hospital in a timely manner to improve the examination, to clarify the cause of the disease, and comply with the doctor’s instructions for targeted treatment, so as not to delay the treatment of the disease.