A disc herniation occurs when the outer wall of the disc (annulus fibrosus) tears, breaks open or ruptures. Some of the matter inside the disc (nucleus pulposus) leaks out and compresses nearby spinal nerves and/or the spinal cord. Although a disc herniation can occur at any level of the spine, the lumbar spine (lower back) and cervical spine (neck) are the most common locations affected. The location of the herniated disc determines where the symptoms are experienced in the body. Symptoms such as numbness and tingling, pain and/or muscle weakness may be experienced in the arm(s) or leg(s) as a result of a herniated disc.