Types according to clinical symptoms: Charles (1952) divided it into seven types: 1, acute lumbar sprain, may be the peripheral periphery of the annulus fibrosus due to fiber rupture, the patient has low back pain but no radiating pain. 2, increased water in the intervertebral disc, such as cosmic pilots in weightlessness stick disc enlargement, but no low back pain, if the injection of drugs (or liquid) into the disc caused low back pain. 3, lumbar intervertebral disc herniation, part of the fiber rupture, to the posterior lateral protrusion, has not yet compressed the nerve root, can cause pain, no true sciatica. 4.The lumbar intervertebral disc is obviously protruded, and there is still a small part of the fiber intact, there is true sciatica, but there is no intervertebral space narrowing on the X-ray film. 5.Mobile fragmentation block in the intervertebral disc, with a large protrusion, still covered with fibers, and with true sciatica. 6.Epidural free intervertebral disc block, the free block may have adhesion with dura or nerve root, there is true sciatica and narrowing of the intervertebral space. 7.Degenerative disc changes, X-ray shows narrowing of the intervertebral space, along with bone spurs, which may or may not be asymptomatic.