(1) Stenosis due to spinal degeneration: thickening of the vertebral plate, stenosis due to vertebral redundancy, hypertrophy of the small joints, thickening of the ligamentum flavum, etc. due to age-related changes and strain on the spine, resulting in volume reduction of the spinal canal. (2) Stenosis due to compound factors: stenosis due to congenital and acquired deformities, stenosis due to disc herniation that reduces the volume of the spinal canal, or stenosis due to a combination of disc herniation and mild stenosis of the spinal canal. (3) Stenosis caused by degenerative vertebral instability, vertebral slippage and osteolysis. (4) Stenosis of medical origin: osteophytes and degeneration of adjacent segments after surgery such as disc removal and lumbar fusion, and scar proliferation and adhesions caused by the use of lysin injection of the nucleus pulposus in disc herniation. (5) Injurious stenosis: such as compression fracture, rupture of the thick wall of the vertebral body protruding into the spinal canal with vertebral dislocation. (6) Other: deformational osteitis (Pagets disease) has spinal deformation and the spinal canal can be narrowed; fluorosis can also cause hyperplastic deformation, resulting in stenosis.