Low back pain with leg pain may be caused by the following reasons: first, lumbar disc herniation, when the lumbar disc herniation compresses the nerve roots, low back pain can occur, accompanied by leg pain, which is often a symptom of sciatica, which can be radiated from the buttocks to the front side of the thigh, calf, and the back of the foot and plantar pain, then CT and MRI of the lumbar spine should be performed for early diagnosis and treatment. Second, lumbar spinal stenosis, when the lumbar spinal stenosis, the protruding discs and proliferating bone spurs can also compress the nerve roots, resulting in back pain with leg pain, then early MRI, X-ray, CT examination should be performed for diagnosis and treatment; third, lumbar spinal slippage, severe lumbar spinal slippage can compress the nerves, resulting in back pain with leg pain, then lumbar spine examination should be performed for diagnosis; fourth, the relatively rare cause is spinal pain. A rare cause is tuberculosis or tumor of the spine, which, if serious, can also compress the nerve and cause back and leg pain.