According to the location, degree, direction of the herniated nucleus pulposus of lumbar disc, the relationship between the degree of degeneration and the nerve root and different imaging examinations, there are various typing methods: pathological typing Although there are various typing methods for lumbar disc herniation, most of them are based on pathological typing, which can be divided into degenerative type, bulging type, herniated type, subdegenerative posterior longitudinal ligament type, postdegenerative posterior longitudinal ligament type and free type. The first three types are end-ruptured, accounting for 77.4%, and the last three types are ruptured, accounting for approximately 37%. The location of the herniation and the spinal canal (cross-section) are classified as central, posterior-lateral, intraforaminal or posterolateral, and extraforaminal or extreme posterolateral. The first two sides are common, accounting for about 85%, while the latter two types are rare and occur more often at the lumbar 3~4 and lumbar 4~5 levels. The central type is also classified as Ⅲ degree, central Ⅰ degree herniation: the herniation is centered but mainly on one side, and the extension is 2mm past the midline; middle bone Ⅱ degree herniation: the herniation is centered but mainly on one side, and the extension is 4mm past the midline; central Ⅲ degree herniation: the herniation is centered and extends to both sides. According to the relationship between the nerve root and the herniated disc, there are supra-shoulder type, anterior shoulder type, and subaxillary type. Supra-shoulder type: the protrusion is located on the lateral side of the nerve root; anterior shoulder type: the protrusion is located on the ventral side of the nerve root, pushing the nerve root backward; subaxillary type: the protrusion is located between the dural sac and the nerve root, and the nerve root is compressed and deformed by upward tortuosity. Morphologic typing: bulging, ruptured and free type. Bulging type: The inner fibrous ring ruptures and the outer layer is bulged by the pressure of the nucleus pulposus, often in a hemispherical shape, isolated and bulging on the posterior lateral side of the intervertebral disc, and in front of or below the outer nerve root (about 30%). The symptoms of nerve root irritation are more obvious, such as skin irritation, but muscle atrophy is not obvious. X-rays may show anterior narrowing and posterior widening of the intervertebral space. Rupture type: the entire or almost complete rupture of the annulus fibrosus (67%), the fibrosed nucleus pulposus or broken annulus fibrosus causes part of the cartilage plate to be displaced backward into the spinal canal, the surface of the protruding mass is uneven and covered only by a membrane, the protrusion is generally more extensive than the raised type, and there may be adhesions with nerve roots. In severe cases, it may compress two nerve roots or produce cauda equina compression syndrome, with lumbar lordosis as the main posture. X-rays show sclerosis of the margins of the nerve roots. Individual imaging shows larger side or anterior compression, central type protrusion I belong to this type. Free type: less common, the protrusion has left the rupture of the protrusion and moved into the spinal canal, or even broken into the dural cavity, can compress the dural sac and irritate the nerve roots, the clinical signs are similar to the rupture type, the nerve root pain is less severe, but the cauda equina nerve compression symptoms are more severe. The non-surgical smelling method is best for the bulging type, followed by the ruptured type, and the free rate type should be treated surgically. Comprehensive typing: Elastic, degenerative instability and hyperplastic stenosis. Elastic type: It is common in young and middle-aged people. It is often accompanied by a history of injury such as fall, flutter, flash, sprain, etc. The onset of the disease is rapid, with significant and persistent low back pain and significant radicular symptoms. Pathologically, the disc tissue of this type is more elastic, the outer fibrous ring is intact, and the protrusion is smooth. X-rays show a normal height of the vertebral body gap, CT shows a hemispherical-shaped herniated mass with neat margins, and there are no abnormal changes in the synovial joint and the yellow ligament. Degenerative instability type: common in middle age. Disease characteristics: Sudden onset of lower limb radiating pain on the basis of chronic low back pain. The slight lumbar flashing and twisting action can be the trigger. It often occurs when the intervertebral disc has obvious degeneration and small joint instability, and the clinical symptoms can be reduced with the change of capital or bed rest. X-ray signs show narrowing of the affected intervertebral space, sclerosis of the intervertebral cartilage plate edges, and displacement of the anterior and posterior edges of the vertebral body. CT shows increased density of intervertebral disc tissue, posterior protrusion, or irregular protruding mass, hypertrophy of the ligamentum flavum, and hyperplasia of small synapses. Hyperplastic stenosis: It is common in middle-aged and elderly people, and is the result of poor regression of the above two types, or spinal stenosis resulting from advanced degeneration of the intervertebral discs and small joints. The clinical features are a history of previous overload or chronic strain, persistent lumbar and leg pain, intermittent claudication, and a fixed change in the physiological curvature of the lumbar spine, which is characterized by limited disc herniation and calcification. There are typical signs of spinal stenosis or lateral saphenous stenosis on X-ray and CT.