Herniated discs are most commonly seen in cervical disc herniation and lumbar disc herniation. Cervical disc herniation is often divided into four types according to its compression site, that is, neurogenic cervical spondylosis, vertebral artery cervical spondylosis, sympathetic cervical spondylosis, and mixed cervical spondylosis; lumbar disc herniation, mainly according to the severity of its protrusion, is divided into four types: first, bulging type, which is the early stage of lumbar disc herniation, at this stage the fibrous ring has just ruptured and the surface layer is intact. Secondly, herniated type, which shows complete rupture of the annulus fibrosus and protrusion of the nucleus pulposus into the spinal canal. Third, prolapsed type, the disc completely prolapses into the spinal canal. Fourthly, the nucleus pulposus enters the cancellous bone of the vertebral body via the upper and lower endplates, and generally this type is not accompanied by more obvious clinical symptoms.