This process happens over an extended period. In many cases, the disc balloons in between spaces in the vertebrae. Movement or slipping of the disc from its normal positioning results in an outward swelling of the fluid material throughout the weakest point of the shell of the disc.
Discs have a hard casing and liquid-like center. Your spine consists of vertebrae which have spinal discs in between to act as a shock absorber, preventing damage to the spinal tissue and bone.