First of all, we have to understand what is called “intervertebral disc”, intervertebral disc is located in the human spine between the two vertebrae, by the cartilage plate, annulus fibrosus, nucleus pulposus composed of a sealed body. The upper and lower cartilage plates are transparent cartilage covering the vertebrae, and the bone surface in the middle of the epiphyseal ring below. The cartilaginous plates above and below, along with the ring of fibers, seal the nucleus pulposus. The annulus fibrosus consists of fibrocartilage with bundles of collagen fibers located around the nucleus pulposus. The fibrous bundles of the annulus fibrosus cross and overlap each other obliquely, making the annulus fibrosus a solid tissue that can withstand large bending and torsional loads. The anterior and lateral sides of the annulus fibrosus are thicker, while the posterior side is thinner. The anterior part of the annulus fibrosus has a strong anterior longitudinal ligament, while the posterior side has a narrower and thinner posterior longitudinal ligament. As a result, the nucleus pulposus tends to protrude posteriorly, compressing the nerve roots or spinal cord and causing a herniated disc. Causes