Low back pain may be caused by strenuous activities in the low back, or it may be caused by certain diseases, such as lumbar muscle strain, herniated discs, etc. 1. Strenuous activity of the low back: Strenuous activity of the muscles of the low back, frequent muscle contraction, which produces a large amount of lactic acid, if not completely broken down and metabolized, will accumulate in the body, causing back pain. 2. Lumbar muscle strain: If long-term excessive lumbar movement and overloading, such as prolonged sitting, standing, lifting objects from bending position to upright position, etc., it is possible that the lumbar muscle is in a state of high tension for a long period of time, resulting in chronic lumbar back muscle strain, and the symptoms of low back pain. 3. Herniated disc: If the annulus fibrosus of lumbar intervertebral disc ruptures, the herniated nucleus pulposus will compress the nerves, which in turn will cause pain in the low back and manifest low back pain. In addition, lumbar back trauma, tumors, urological diseases, etc. may also cause low back pain, if a long time can not be relieved by themselves, should promptly consult a doctor to clarify the cause of the disease, and then give targeted treatment.