One cause of back pain or neck pain can be a herniated disk, sometimes called a slipped disk or a ruptured disk.
Your spine is made up of bones (vertebrae) cushioned by small oval pads of cartilage or disks consisting of a tough outer layer (annulus) and a soft inner layer (nucleus).
When a herniated disk occurs, a portion of the nucleus pushes out through a tear in the annulus into the spinal canal. This can irritate and inflame a nerve and result in pain, numbness or weakness in your back or neck as well as your leg(s) or arm(s).
You can have a herniated disk without knowing it — herniated or bulging disks sometimes show up on spinal images of people who have no symptoms of a disk problem. But some herniated disks can be painful.