Bulging and Herniated discs
The vertebral discs are made of a tough outer layer and soft inner gelatin-like center. When a disc is herniated, there is actually a crack in the outer layer that allows the softer inner core to protrude out. A bulging disc differs in that there is no leaking of the inner core. In this case, the outer layer is intact but bulging out in a place where the outer wall has weakened. Where they are the same is the excruciating pain caused by both instances.