The bones that form the spine in your back are cushioned by small, spongy discs. When these discs are healthy, they act as shock absorbers and keep the spine flexible. But when a disc is damaged, it may bulge or break open. This is called a herniated disc. It may also be called a slipped or ruptured disc. Patients can have a herniated disc in any part of their spine. But most herniated discs affect the lower back, or lumbar spine. Some can happen in the neck and even in the upper back.
When a herniated disc presses on nerve roots, it can cause pain, numbness, and weakness in the area of the body where the nerve travels. A herniated disc in the lower back can cause pain and numbness in the buttock and down the leg. This is called sciatica. Sciatica is the most common symptom of a herniated disc in the low back.