The terms slipped disc, herniated disc, bulging disc, ruptured disc are all commonly used terms to refer to a condition in which the inner part of the intervertebral disc called the nucleus pulposus pushes through the outer containing fibers of the disc called the anulus fibrosus. This bulging of the inner nucleus into the anulus fibrosus can take two forms. If the nucleus is held within the anulus fibrosus, the process is termed a contained disc
, and sometimes referred to as a disc protrusion or herniation. If the anulus fibrosus tears and allows the inner nucleus pulposus to escape through the anlus fibrosus it is called a non-contained disc herniation
and often called a ruptured or fragmented disc.
Whether the disc is contained or non-contained, it is possible that the disc can press on a nerve with sufficient pressure to mechanically irritate a nerve to cause back, neck, arm or arm pain, or in the case of the non-contained disc to chemically irritate the nerve by chemical reaction of the free nucleus pulposus material contacting the nerve.