What causes an intervertebral disc to herniate?

A herniated disc (from the Latin hernia, meaning “to bulge” or “stick out”) occurs when the soft inner part of an intervertebral disc protrudes through a weakened or torn outer ring and pushes against a spinal nerve. A herniated disc may be the result of an injury or degeneration of the intervertebral joint. Although herniated discs may occur anywhere along the spine, they are most common in the lumbar or sacral regions.