What is the difference between a herniated disc and a bulging disc?
A herniated disc is “non-contained” which means that a tear or break is present and a section of the gel-like nucleus pulposus has slipped into the spinal canal while a bulging disc is “contained“, meaning that the outer layer of the disc does not have any tears or ruptures, and no portion of the nucleus has leaked out of the disc.
Discs act as cushions between the vertebrae in the spine and are composed of an outer layer of tough cartilage (annulus) and softer cartilage in the center (nucleus). Functionally, discs are responsible for absorbing impact, maintaining spacing between the vertebrae, and preserving mobility. The annulus may break down as a result of repeated trauma and the natural process of aging, making the nucleus push through the annular cartilage.
During a herniated disc, which is considered "non-contained", a portion of the nucleus leaks into the spinal canal as a result of a tear or rupture in the annulus.
Bulging discs are quite common in both young adults and older people
If you have a bulging disc, as it presses on a nerve, you will experience symptoms in whatever part of your body the affected nerve serves. Both bulging and herniated discs can sometimes press against the spinal cord and the following symptoms can appear depending on where the disc is located in your thoracic or cervical spine: