Wear and tear, also called disc degeneration, is the usual cause of a herniated disc. As we age, the discs in our back lose some of the fluid that helps them stay flexible. The outer layer of the discs can form tiny tears or cracks. The thick gel inside the disc may be forced out through those cracks and cause the disc to bulge or break open.
This can also happen when you injure your back. Injury can occur from:
A sudden heavy strain or increased pressure to
the lower back. Sometimes a sudden twisting movement or even a sneeze will
force some of the material out.
Activities that are done over and
over again that may stress the lower back, including poor lifting habits,
prolonged exposure to vibration, and sports-related injuries.