Animation of a spinal disc herniation causing lower back pain. The spinal column is made up of vertebrae separated and cushioned by intervertebral discs (yellow). Herniation occurs when the capsule of a disc weakens and the gel-like inner mass deforms and protrudes through it. This can press against the spinal cord or the nerves that emerge from it, causing pain, weakness and numbness. It is a common occurance with advancing age. Treatment includes exercises to strengthen the back muscles, correcting posture and losing weight. Surgery may be required in severe cases.