Introduction

The discs are protective shock-absorbing pads between the bones of the spine (vertebrae).
These discs are round and flat, with a tough, outer layer (annulus) that surrounds a jellylike material called the nucleus.
A herniated disc (also called a bulged, slipped or ruptured) disc is a fragment of the disc nucleus that is pushed out of the annulus, into the spinal canal through a tear or rupture in the annulus.
Discs that become herniated are usually in an early stage of degeneration.Herniated discs are more common in the lower back (lumbar spine), but also occur in the neck (cervical spine).