The spine ages with you. Intervertebral discs begin to degenerate by the third decade of life. Unless a herniated disc is caused by a traumatic injury, the stages are usually gradual and associated with the toll taken on by the daily wear and tear on the spine.

Stages of Disc Herniation

Stage 1: Degeneration
As the disc dehydrates with age, it begins to lose elasticity and becomes brittle.

Stage 2: Bulging Disc Herniation
Over time tiny tears may form in the outer, fibrous ring (annulus fibrosus) of an intervertebral disc allowing the soft, gel-like central portion (nucleus pulposus) to bulge out or produce a "bubble" along the tough fibrous outer layer. This is often referred to as a "bulging" disc or contained herniation or sub-ligamentous herniation. A bulging disc is often informally and misleadingly called a "slipped disc."

Stage 3: Extrusion
Next, a disc extrusion occurs when part of the nucleus breaks through the tough fibrous outer layer (annulus fibrosus ) but still remains within the disc. This type of lumbar herniation may also be referred to as a non-contained herniation or trans-ligamentous herniation.

Stage 4: Sequestration
Finally, a disc sequestration occurs when the leaking gel-like material (nucleus pulposus) breaks through the tough outer layer (annulus fibrosus) and is loose within the spinal canal. This may also be referred to as a free fragment.

Stage 2

Stage 3

Stage 4