A herniated disc, also known as a slipped disc, is a medical condition that affects the spinal discs. A spinal disc is a soft, round cushion that sits between the vertebrae (the bones of the spine). The discs act as shock absorbers and help to keep the spine flexible.

A herniated disc occurs when the inner gel-like core of the disc bulges out through a crack in the tough outer layer. This can cause pain, numbness and tingling in the back and down one or both legs. In many cases, conservative measures such as pain relief and physical therapy can help relieve symptoms.