It is mainly because all parts of lumbar intervertebral disc (nucleus pulposus, annulus fibrosus and cartilage plate), especially nucleus pulposus, are degenerated to varying degrees. Under the action of external factors, the annulus fibrosus of intervertebral disc ruptures, and the nucleus pulposus tissue protrudes (or protrudes) from the ruptured site to the back or the spinal canal, which leads to the stimulation or compression of adjacent spinal nerve roots, resulting in a series of clinical symptoms such as low back pain, numbness, and pain in one or both lower limbs. The highest incidence rate of lumbar disc herniation is lumbar 4 ~ 5 and lumbar 5- sacrum 1, accounting for about 95%.

The cause of disease

1. Lumbar intervertebral disc degeneration is the basic factor.

The degeneration of nucleus pulposus is mainly manifested by the decrease of water content, which can cause small-scale lesions such as instability and loosening of vertebral segments due to water loss. The degeneration of annulus fibrosus is mainly characterized by decreased toughness.

2. Damage

Long-term repeated external forces cause minor injuries and aggravate the degree of degeneration.

3. The weakness of the anatomical factors of the intervertebral disc itself.

In adulthood, the intervertebral disc gradually lacks blood circulation and its repair ability is poor. On the basis of the above factors, some inducing factors that can lead to the sudden increase of intervertebral disc pressure may make the nucleus pulposus with poor elasticity pass through the fibrous ring that has become less tough, thus leading to nucleus pulposus protrusion.

4. Genetic factors

There are reports of familial lumbar disc herniation.

5. Lumbosacral congenital anomaly

Including lumbosacral, lumbosacral, hemivertebra deformity, facet joint deformity and facet joint asymmetry. The above factors can change the stress on the lower lumbar spine, and increase the internal pressure of the intervertebral disc, which is prone to degeneration and injury.

6. Inducing factors

On the basis of intervertebral disc degeneration, some factors that can induce the sudden increase of intervertebral space pressure can cause nucleus pulposus protrusion. Common inducing factors include increased abdominal pressure, improper waist posture, sudden weight bearing, pregnancy, cold and dampness, etc.