Some people develop a bulging disc or herniated disc in their neck or back. Injury, aging and poor lifestyle choices may increase the risk for a disc problem. Bulging discs are more common than herniated discs and usually cause no pain.
Discs are composed of a tough outer layer of cartilage that surrounds a softer material in the center. Discs are the soft, gelatinous material that cushions the vertebrae of the spine. It may help to think of them as miniature jelly doughnuts between your vertebrae.
A bulging disc simply extends outside the space it should normally occupy. The bulge typically affects a large portion of the disc, so it may look a little like a hamburger that's too big for its bun. Usually bulging is considered part of the normal aging process of the disc and is therefore common to see on a magnetic resonance image (MRI).
In the majority of patients who experience a bulging disc, there is no pain unless the disc becomes herniated or protrudes into a nerve. Bulging disc pain which radiates to the shoulders and arms generally indicates that a nerve in the neck may be pinched or pushed upon. In the lower back, pain may sometimes radiate to the legs.
A bulging disc is different from a herniated disc in that a bulging disc typically occurs gradually over time rather than suddenly. A bulging disc is one in which the tough outer layers of the disc simply bulge into the spinal canal. A bulging disc could be compared to a volcano prior to eruption and may be a precursor to herniation. The disc may protrude into the spinal canal without breaking open.
A herniated disc is often the result of an injury or trauma to the spine. It results when a crack in the tough outer layer of cartilage allows some of the softer material inside to protrude out of the disc. Herniated discs are also called ruptured discs or slipped discs.
Herniated disc pain occurs when the disc's gel-like nucleus (which contains a chemical) irritates the nerves causing them to swell. After the chemical agent has done its job, the remnants of the chemical remain and continue to press on the irritated and swollen nerves.