What is the difference between a herniated disc and bulging disc?
A normal healthy disc has a usual height and shape. As a disc begins to degenerate and lose its normal water content, it begins to lose some of its ligamentous strength. With this loss of water content, there is usually a loss of height, which causes the edge of the disc to protrude beyond the edges of the bone. This is comparable to letting air out of a car tire. As a car tire loses air, the tire broadens out as it loses height. The same is true for a disc. When the disc extends beyond the normal edge of the bone by greater than 50% of the circumference, it is termed a bulging disc.
