herniated disk, a rupture of the fibrocartilage surrounding an intervertebral disk, releasing the nucleus pulposus that cushions the vertebrae above and below. The resultant pressure on spinal nerve roots may cause considerable pain and damage the nerves, resulting in restriction of movement. The condition most frequently occurs in the lumbar region. Also called herniated intervertebral disk, herniated nucleus pulposus, ruptured intervertebral disk, slipped disk.
