Definition according to the Mayo Clinic
A herniated disk refers to a problem with one of the rubbery cushions (disks) between the individual bones (vertebrae) that stack up to make your spine.
A spinal disk is a little like a jelly donut, with a softer center encased within a tougher exterior. Sometimes called a slipped disk or a ruptured disk, a herniated disk occurs when some of the softer "jelly" pushes out through a crack in the tougher exterior.
A herniated disk can irritate nearby nerves and result in pain, numbness or weakness in an arm or leg. On the other hand, many people experience no symptoms from a herniated disk. Most people who have a herniated disk don't need surgery to correct the problem.
Experiences from bellicon users with herniated disks: