Herniated disc

Herniated disc or herniated nucleus pulposus (HNP) occurs with age or injury, the center of vertebral discs may start to lose water content, making the disc less effective as a cushion, causing displacement of the disc's center (herniated or ruptured disc) through a crack in the outer layer. Most disc herniations occur in the bottom two discs of the lumbar spine, at and just below the waist. A herniated disc can press on a nerve root in the spine and may cause back pain or pain, numbness, tingling or weakness of the leg called sciatica or radiculopathy. Also known as a slipped or ruptured disc, or herniated nucleus pulposus (HNP). Can also occur in the neck  and lumbar but rarely in the thoracic portion of the spine.