Lumbar pain leading to leg pain on one side can be considered to be caused by lumbar spinal stenosis or lumbar intervertebral disc herniation. 1. Lumbar spinal stenosis: mostly caused by degenerative changes in lumbar spinal canal, such as narrowing of the intervertebral space, bone redundancy formation, etc., most of the middle-aged and elderly onset of back pain for many years, and then appeared on one side or both sides of the lower extremity pain, pain aggravated after standing or walking. 2. Lumbar intervertebral disc herniation: lumbar intervertebral disc degeneration, under the action of external forces, the fibrous annulus ruptured partially or completely, protruding outward, can irritate or oppress the sinus nerve and nerve root, most of the patients with lumbar pain, and gradually sciatica, caused by the buttocks, thighs or calves and other parts of the radioactive pain. It is recommended to go to the hospital specialist in time to improve the lumbar CT or MRI and other related examinations, and then follow the doctor’s instructions for treatment.