In the clinic, I often encounter such questions.” Doctor! I have back and leg pain. The doctor says I have a lumbar disc herniation and the MRI says I have a bulging disc. How can I explain this bulge and herniation? Is there a connection between them?” The American Academy of Orthopaedic Surgeons defines the nomenclature of disc lesions as follows: 1. Normal disc: no disc degeneration, all disc tissue is within the intervertebral space. 2. Disc bulge (degeneration): the annulus fibrosus is uniformly beyond the intervertebral space and the disc tissue does not protrude in a restricted manner and remains within the intervertebral space. (No nerve irritation symptoms) 3, disc herniation: limited displacement of disc tissue beyond the intervertebral space, the displaced disc tissue is still connected to the original disc tissue, and the diameter of its basal continuous part is larger than the displaced disc part beyond the intervertebral space. (More nerve root symptoms of low back pain + leg pain and over the knee) 4, disc prolapse: The diameter of the displaced disc tissue is greater than the basal contiguous portion and moves beyond the intervertebral space. The prolapsed disc tissue block is larger than the ruptured disc fissure and is located in the spinal canal through this fissure (cauda equina syndrome with perineural numbness and dysfunctional bowel). To deepen understanding, the onset/development of disc lesions from a pathological perspective (disc cross-section): A. Disc bulge: increased intramedullary pressure, rupture of the inner layer of the fibrous annulus, and bulging of the middle and outer fibrous annulus. The annulus fibrosus is uniformly beyond the intervertebral space and the disc tissue does not protrude in a restrictive manner and remains within the intervertebral space. B. Disc herniation: The disc fibrous ring ruptures in its entirety, the nucleus pulposus prolapses from the rupture, and the disc tissue is limitedly displaced beyond the disc space, jacking up the posterior longitudinal ligament. The displaced disc tissue is still attached to the original disc tissue, and its basal continuum is larger in diameter than the displaced disc portion beyond the intervertebral space. C. Disc prolapse: A large nucleus pulposus prolapses and penetrates the posterior longitudinal ligament. However, the displaced disc tissue is still attached to the original disc tissue, and the diameter of the displaced disc tissue is larger than the basal contiguous portion and moves beyond the intervertebral space. The dislocated disc tissue is larger than the ruptured disc fissure and is located within the spinal canal through this fissure. D. Disc prolapse (free type): the prolapsed nucleus pulposus tissue leaves the fissure of the fibrous annulus completely and is free in the spinal canal. The displaced disc tissue is not connected to the original disc tissue. The general mainstream view is that lumbar disc bulge should be a manifestation of disc aging, degeneration and relaxation, and generally does not produce symptoms. If an elderly patient has spinal canal or lateral saphenous stenosis, the symptoms should belong to spinal stenosis; however, some people believe that bulging can produce pain and decompression. In theory, for bulging if the nucleus pulposus is removed by protrusion or percutaneous resection, it is bound to be more bulging after surgery. In fact: intervertebral disc aging (degeneration) can be divided into two categories: physiological aging and pathological aging, physiological aging refers to the ageing of the organism since the beginning of maturity, affected by genetic factors, progressive systemic complex morphological structure and physiological function of irreversible degenerative changes, also known as normal aging. Pathological aging refers to the accelerated and early aging caused by diseases or abnormal factors, which is also called pathological aging. However, physiological aging and pathological aging only have theoretical significance, in practice it is difficult to distinguish between the two often exist at the same time, affecting each other, promoting each other, mutual cause and effect, resulting in a vicious circle, accelerating aging. Therefore, the disc bulge from the occurrence and development, should be pathological. Only the absence of clinical symptoms, is generally not considered a disease. In the clinical practice of lumbar disc lesions, medical personnel put more emphasis on the combination of “symptoms” and pathology, with “symptoms” as the main focus. For example, in the case of lumbar disc herniation (lumbar pain + sciatic leg pain) and lumbar disc prolapse (cauda equina syndrome), the main emphasis is on one “symptom” (symptom), and the treatment is all about the “symptom”. Patients with “symptoms” are treated, while those without “symptoms” are generally not treated. And the choice of treatment such as conservative treatment or surgery depends entirely on the symptoms combined with the pathology to coordinate. The lumbar disc bulge should belong to the intervertebral disc aging, degeneration, relaxation, generally do not produce symptoms. Of course, there is no need to consider whether to treat. Therefore, the disc bulge is neither normal intervertebral disc; nor is the disc herniation “disease” and disc prolapse “disease” that can produce clinical symptoms. Pathologically speaking, he should belong to the aging and degeneration of the intervertebral disc that does not produce clinical symptoms, without special treatment. However, clinically speaking, it should still be raised to a high level of pathology to understand and do a good job of preventing lumbar disc herniation.