What occurs in a herniated disc?

In a herniated disc, the condition specifically involves the inner gel-like substance of the spinal disc, known as the nucleus pulposus, protruding through a tear or weakness in the outer layer of the disc, referred to as the annulus fibrosus. This displacement can put pressure on nearby spinal nerves, leading to pain, numbness, or weakness in the limbs, depending on the location of the herniation.

This herniation process is often caused by degenerative changes in the disc from aging or an injury. When the outer layer is intact, the disc maintains its shape and function. However, when the inner material pushes through, it indicates that the outer layer has been compromised, allowing for this bulging or rupture. The other choices do not accurately describe the herniation process; rather, they relate to different conditions affecting spinal discs.