Causes of low back pain include lumbar muscle strain, lumbar disc herniation, urinary stones, nephritis, and so on. 1. Lumbar muscle strain: mostly seen in sedentary and standing for a long time or over-exercise crowd, often manifested as soreness and discomfort of the lumbar muscles, which can be relieved after rest. 2. Herniated lumbar intervertebral disc: caused by degenerative lesions or poor posture due to prolonged sitting, the protruding lumbar intervertebral discs cause nerve compression symptoms, resulting in lumbar pain, and in severe cases, it can cause numbness of the legs, feet and other nerve compression symptoms. 3. Urinary stones: urinary stones can cause low back pain symptoms, mainly seen in the ureteral stones. When the stones cause different degrees of ureteral obstruction, hydronephrosis will occur, causing severe back pain symptoms. 4. Nephritis: Acute glomerulonephritis or acute progressive glomerulonephritis may cause low back pain in the early stage due to the increase of kidney volume and dilation of kidney peritoneum. Patients with symptoms of low back pain, there are many other reasons, you need to go to the hospital in time for examination, to clarify the cause of the disease, with the doctor for targeted treatment.