Back muscle pain is mainly caused by fasciitis, physiological factors such as lactic acid buildup due to overwork, osteoporosis, autoimmune diseases and spinal pathologies. 1. Fasciitis: mostly caused by strain injury, is to maintain the same posture for a long time leading to back muscle tension and spasm for a long time aseptic inflammation occurs, causing back muscle aches and pains. 2. Physiological factors: such as a large number of sports or excessive exercise caused by the accumulation of muscle lactic acid. 3. Osteoporosis: mostly occurs in menopausal women and the elderly, there is no fixed pressure point, through the X-ray film and bone density examination can be clearly diagnosed. 4. Autoimmune diseases: such as ankylosing spondylitis, accompanied by morning stiffness, most of the patients have positive HLAB27 in hematology. 5. Spinal lesions: mainly degenerative spinal lesions such as lumbar intervertebral disc herniation and lumbar spinal stenosis. The cause of back muscle pain is more complex, physiological factors and fasciitis caused by soreness can be relieved after rest or disappear, if the pain is recurring or aggravated, you need to consult a doctor in time.