Sciatica can be caused by trauma, lumbar disc herniation, degenerative lumbar spine disease, pyriformis syndrome and so on. 1. Trauma: such as impact, fall, etc., sciatica is accompanied by muscle or bone pain, redness and swelling of the damaged area. 2. Lumbar disc herniation: caused by chronic strain injury, long-term bending, disc degeneration, etc., manifested as sciatica and lower limb pain, stiffness and numbness. 3. Lumbar degenerative disease: including lumbar spondylolisthesis, spinal stenosis, vertebral osteophytes, etc., with specific symptoms of sciatica and intermittent claudication. 4. Piriformis syndrome: refers to trauma to the buttocks, cold, fracture, etc., so that the piriformis muscle is damaged and presses the sciatic nerve, resulting in sciatica, radiating pain in the buttocks and lower limbs. In addition, pregnancy, obesity, long-term smoking may also lead to sciatica. If you want to clarify the cause of the disease, you should go to the hospital in time to improve the examination, under the guidance of the doctor for specialized treatment.