The spinal column is made up of bones called vertebrae that are stacked on top of each other to protect the nerves of the spinal cord. In between the stacked vertebrae are small rubbery intervertebral discs that provide cushioning to keep the spine flexible and act as shock absorbers. The spinal discs are made up of a tough, outer shell (annulus) surrounding a jelly-like center (nucleus pulposus).
When the discs deteriorate with age, they can lose fluid and dry out. As this happens, they become bulging discs that compress and bulge out. This is a degenerative process with a progressive, gradual onset of symptoms.
A herniated disc may be the result of the progression of bulging discs, or a sudden injury to the spine. A herniated disc, also called a slipped disc or ruptured disc, occurs when pressure from the vertebrae above and below these cushioning discs force some or all of the nucleus pulposus (the soft, gel-like center) through a weakened or torn part of the annulus (the tough, fibrous outer layer). The herniated nucleus pulposus can squeeze and irritate 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 (neck) and thoracic (mid-section) spine. A herniated disc is one of the most common causes of neck, back, and sciatica leg pain and neck-ache.
Many people have no symptoms from a herniated disk. Surgery is usually not necessary to relieve the problem.
Many people with herniated discs have no symptoms. Pain happens when the bulging disc irritates the membrane outside the spinal cord or spinal nerves. It usually affects one side of the body.
- Arm or leg pain: If your herniated disc is in your lower back, you’ll typically feel the most pain in your buttocks, thigh, and calf. You might have pain in a part of the foot, as well. If your herniated disc is in your neck, you’ll typically feel the most pain in your shoulder and arm. This pain might shoot into your arm or leg when you cough, sneeze, or move into certain positions. Pain is often described as sharp or burning.
- Numbness or tingling: Frequently, people who have a herniated disc have radiating numbness or tingling in the body part served by the affected nerves.
- Weakness: Muscles served by the affected nerves tend to weaken. This can cause you to stumble or affect your ability to lift or hold items.
You can have a herniated disk without symptoms. You might not know you have it unless it shows up on a spinal image.