Lumbar disc herniation is the full name of “lumbar disc rupture” + “nucleus pulposus herniation”. It is one of the common clinical diseases of low back and leg pain. It accounts for about 20% of outpatient lumbar pain. It is a disease caused by the degeneration and injury of the lumbar intervertebral disc, which leads to the imbalance of the internal and external mechanical balance of the spine, causing the nucleus pulposus of the intervertebral disc to protrude from the rupture of the annulus fibrosus and compress the lumbar spinal nerve roots, resulting in low back pain. Clinical protrusion is most common between lumbar 4~5 and lumbar 5~sacral 1. To understand its pathogenesis, we must first understand the anatomical and physiological structure of the lumbar intervertebral disc: the intervertebral disc consists of three parts: the nucleus pulposus, the fibrous ring and the cartilage plate, which is a flexible cushion connected between the upper and lower vertebral bones, and the posterior spinal joints form the basis of spinal motion, and at the same time can withstand pressure and cushion shock. There are anterior and posterior longitudinal ligaments in front of and behind the vertebral body and intervertebral disc respectively, with the anterior longitudinal ligament being wide and strong and the posterior longitudinal ligament being narrow. They protect the intervertebral discs. The causes of lumbar disc herniation can be divided into endogenous and exogenous: I. Endogenous factors 1, anatomical structure of their own weakness factors: lumbar intervertebral disc fiber ring anterior and both sides thicker, the posterior side is weaker, and the posterior side of the fiber ring between the layers of bonding material less than the front and both sides of the solid; fiber ring of the anterior part of the strong anterior longitudinal ligament to strengthen, the posterior side of the posterior longitudinal ligament, but narrower and thinner, and since the first lumbar plane below The posterior longitudinal ligament is gradually narrowed to the 5th lumbar vertebra and the 1st sacral vertebra, and the width is only half of the original one. The lumbosacral part is the part that is subject to the greatest dynamic and static forces, and these weaknesses in its natural structure cause the nucleus pulposus to protrude easily to the rear on both sides. 2, the degeneration of the intervertebral disc: it is generally believed that the intervertebral disc is the earliest and most prone to degenerative changes in the human body with age, and has a significant relationship with strain and trauma, but also with lifestyle habits, occupation, systemic conditions and endocrine have a certain relationship. Degeneration generally begins after the age of 20, due to the increased opportunities for weight bearing and spinal movement, the intervertebral disc is often subjected to extrusion, tension and torsional stress from various forces, thus making the disc prone to dehydration, fibrosis, atrophy, and gradually lose elasticity and toughness. Degeneration generally starts from the cartilage plate and gradually ossifies, its permeability decreases, the water in the nucleus pulposus gradually decreases, and eventually fibrosis is formed, degenerating into a fibrocartilaginous entity, which leads to thinning of the intervertebral disc, narrowing of the intervertebral space, loosening of the anterior and posterior longitudinal ligaments, resulting in imbalance of the internal and external mechanical balance of the spine, destabilization of the vertebral body, and finally the rupture of the fibrous ring from the inside out due to external factors such as trauma, strain, and cold. This is the main reason for the occurrence of the disease. Second, external causes 1, trauma and strain injury: especially the accumulative strain injury, is an important factor causing the disease. The intervertebral disc is deformed when bending activities or under pressure, at this time, the disc’s ability to absorb water is reduced until the pressure is lifted, the deformation and the ability to absorb water can only be restored. If long-term bending work, or lumbar accumulative strain injury, to the nucleus pulposus does not get normal filling for a long time, the fiber ring nutrient supply is also inadequate for a long time, coupled with increased muscle tension in the lumbar back, resulting in increased pressure in the intervertebral disc, so a slight external force can also make the fiber ring rupture and cause the nucleus pulposus to protrude. When bending over to carry heavy objects, also and easy to cause the occurrence of this disease. Because the lumbar spine is arranged into a physiological convexity, the lumbar intervertebral disc is thick at the front and thin at the back, and the nucleus pulposus is located in the central back. When a person bends forward, the vertebral space becomes narrow in front and wide in the back, the disc becomes thin in front and thick in the back, the nucleus pulposus is displaced backward, and a strong resistive elastic force is generated, which causes the nucleus pulposus to be displaced backward. If the weight is greater, this backward elasticity will be greater, it is likely to make the nucleus pulposus break through the fibrous ring and protrude to the side and back, causing irritation or compression symptoms of the spinal nerve root, spinal cord or cauda equina. 2, cold stimulation: long-term cold stimulation, so that the lumbar back muscle tension contraction, affecting local blood circulation, which in turn affects the nutritional supply of the intervertebral disc. At the same time, due to muscle tension spasm, resulting in increased pressure in the intervertebral disc, especially for the degenerated intervertebral disc, can cause further damage, resulting in nucleus pulposus protrusion.