What is a slipped disc, and why does it hurt so much?

Your spine consists of 33 bones called vertebrae. In-between each
vertebra are circular pads, or discs, of connective tissue, which protect
the vertebrae against shocks. The discs have tough cases that contain a
gel-like substance.

A slipped disc occurs when the gel protrudes outwards between the
vertebrae. A damaged disc can put pressure on the entire spinal cord or on
a single nerve fibre. This means that not only will a person with a slipped
disc feel pain around the disc, but they could potentially also feel pain in
every area a nerve fibre controls.