A disc herniation occurs when the outer walls of the intervertebral disc (annulus fibrosis) tear. Other terms for this are “ruptured disc,” “prolapsed disc,” or “slipped disc.” When outer annular rings tear, the central gel like nucleus pulposus can push out pressing on the structures in the area. The herniation usually occurs at the posterior lateral wall where the annulus fibrosis is thinnest. Unfortunately this is where the nerves of the spine exit and track distally to the body. The larger the tear and the further the nucleus push out, the more severe the symptoms. Disc herniation can be caused by the following:
Degeneration or general wear-and-tear which can break down the walls of the disc.
Repetitive bending and twisting motions especially in combination. These motions place the most stress on the outer fibrous rings.
Discs are most susceptible to injury in the sitting or bending position as the pressure on the disc is displaced to the front pushing the contents of the disc posterior laterally toward the thinner weaker annulus fibrosis.
A sudden fall or trauma, like a motor vehicle accident, can result in a disc herniation.
Genetic factors can contribute to the likelihood of intervertebral disc disease.