What is a herniated disc?

The spine, or backbone, is made up of a series of individual bones called vertebrae that are stacked to form the spinal column. Between the vertebrae are flat, round cushioning pads called intervertebral discs, which act as shock absorbers. Each disc has a soft, gel-like center — called the nucleus pulposus — surrounded by a tough, fibrous outer layer called the annulus.

A herniated disc — also called a slipped disc or ruptured disc — occurs when pressure from the vertebrae above and below force some or all of the nucleus pulposus through a weakened or torn part of the annulus. The herniated nucleus pulposus can press on the nerves near the disc, resulting in pain.

Herniated discs most frequently occur in the lower part of the spine; however they can also occur in the cervical and thoracic spine. A herniated disc is one of the most common causes of neck, back and/or leg pain (sciatica) and neckache

How common are herniated discs?

Herniated discs are very common. They occur more often in people aged 35 to 55 years. They are more common in men than in women.

What are the symptoms of a herniated disc?

Herniated discs often produce no symptoms at all. Symptoms of a herniated disc in the low back include:

  • Pain that radiates to the buttocks, legs, and feet — called sciatica (Back pain might or might not be present, as well)
  • Tingling or numbness in the legs or feet
  • Muscle weakness

Symptoms of a herniated disc in the neck include:

  • Pain near or over the shoulder blade
  • Pain that radiates to the shoulder, arm, and — sometimes — the hand and fingers
  • Neck pain, especially in the back and on the sides of the neck (The pain might increase when bending or turning the neck)
  • Spasm of the neck muscles

Symptoms of a herniated disc in the mid-back tend to be vague. There might be pain in the upper back, lower back, abdomen, or legs, as well as weakness or numbness in one or both legs.

What causes a herniated disc?

A herniation occurs when the outer part of the disc, the annulus, becomes weak and tears. Several factors can contribute to disc-weakening, including

  • Aging and degeneration
  • Excessive weight
  • A sudden strain from improper lifting or from twisting violently

What complications are associated with a herniated disc?

Chronic (ongoing) back or leg pain and loss of control or sensation in the legs or feet are some complications of an untreated disc herniation.