The Facts
The spine is made up of bones called vertebrae. Between the bones of the spine are small discs made of a thick layer of cartilage on the outside and a soft and jelly-like material on the inside. The discs act to absorb shocks caused when the spine moves and allow the spine to bend.
The spinal cord is a bundle of nerves running through the canal within the spinal column. It carries messages to and from the brain via nerve roots that branch out to the body along the length of the spinal cord. A herniated, prolapsed, or ruptured disc happens when the inner material bursts through the outer lining of cartilage and puts pressure on or damages the spinal nerves.
Herniated discs can occur in any part of the spine, but they are most common in the lower back (lumbar section of the spine). Herniated discs are more common in people between 30 and 40 years old.