The bones (vertebrae) that form the spine, including the neck and low back are separated and cushioned by small discs that act as shock absorbers . A herniated disc, also known as a bulged, slipped or ruptured disc, occurs when the inner jelly-like material (nucleus) pushes out of the outer layer (annulus). Discs most often displace out posteriorly into the spinal canal which can press on soft tissue and spinal nerves producing pain.