What is a herniated disc?
The bones (vertebrae) that form the spine in your back are cushioned by small, spongy discs. When these discs are healthy, they act as shock absorbers for the spine 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.
You can have a herniated disc in any part of your spine. But most herniated discs affect the lower back (lumbar herniated disc). Some happen in the neck (cervical herniated disc). Less often, they can be in the upper back (thoracic herniated disc).
Types of herniated discs
Cervical disc herniation
A cervical herniated disc, also known as a slipped or ruptured disc, occurs when a disc in the neck area (cervical) of the spinal column is damaged by injury, disease or the normal wear and tear of aging.
Lumbar herniated disc
A lumbar herniated disc is a ruptured disc in the lower back. A normal disc has a tough outer layer and a softer, jelly-like center. When a disc becomes compressed due to injury or disease, it bulges out from its normal position and comes in contact with nerves. This is the most common kind of herniated disc.
A slipped disc, also known as a herniated or ruptured disc, is a condition that occurs when the disc moves out of alignment in the spine and cracks, causing the soft, gel-like inner material to leak out.
Even if a cervical herniated disc, or ruptured disc, has not caused significant spinal cord compression, it may cause neck pain without any other symptoms. If the spinal cord is compressed, you may develop symptoms of cervical herniated disc such as:
- Painful "pinched" nerves
- Weakness in one or both arms
- Weakness in hands, especially when gripping or shaking hands
- Weakness in one or both legs
- Numbness or paresthesia (pins and needles)
- Difficulty with fine motor activities of your hands, such as buttoning your shirts
- Difficulty with walking
- Difficulty controlling your bowel or bladder function
If the nerve roots are compressed (in cases of acute cervical herniated discs), symptoms may also include neck pain that radiates down your arms and hands on one side of your body.
The symptoms of a lumbar herniated disc vary depending on which disc has ruptured and the specific nerve root it presses. The following are the most common symptoms of a lumbar herniated disc:
- Intermittent or continuous back pain—Sometimes made worse by movement, coughing, sneezing, sitting or standing for long periods of time
- Lower back spasms
- Sciatica—Pain that starts near the back or buttocks and travels down the leg to the calf or into the foot
- Muscle weakness—In the legs or lower back
- Numbness—Usually involving the leg or foot
- Decreased reflexes—Affecting the knees or ankles, due to a herniated disc in the lumbar section
Incontinence of urine or stool can also occur in severe cases and is considered a serious condition requiring rapid evaluation and treatment.
Causes of cervical disc herniation include:
- Degenerative spine disease—This is the most common cause of a cervical ruptured disc, brought about by the natural wear-and-tear process of aging. Over time, the ligaments and exterior of the disc spaces weaken and allow the disc contents to bulge or expel out of the normal disc space.
- Spine injuries—Traumatic injuries may cause cervical herniated discs by creating tiny tears or cracks in the outer layer, or capsule, of the disc and forcing the jellylike nucleus of the disc to bulge, rupture or break into fragments.
Additionally, people who smoke are at a much higher risk for developing herniated discs than nonsmokers are.
The primary causes of a lumbar herniated disk are:
- Aging—With aging, our spinal discs slowly degenerate. They begin to dry up and lose some of the elasticity that keeps them flexible and cushion-like. When a disc dries out, the normal structure of the disc weakens and bulging and rupture of the disc can occur.
- Trauma—Direct trauma to the spine can crack or tear the disc due to:
- Sudden increased pressure or heavy strain to the lower back
- Sudden twisting movements
- Sports-related injuries
- Poor lifting habits
- Repetitive activities
- Prolonged exposure to vibration
A slipped disc can be the result of a number of things, such as:
- Improper bending or lifting
- Overextension of the back or neck
- Age-related degeneration
- Trauma, injury or strain
How is it diagnosed?
In addition to a complete medical history and physical examination, diagnostic procedures for a lumbar herniated disc may include the following:
- X-ray—Invisible electromagnetic energy beams produce images of bones on film. These are very useful to see the overall alignment of the vertebrae and to look for arthritic changes.
- Magnetic resonance imaging (MRI)—A combination of large magnets, radiofrequencies and a computer produces detailed images of the spine, including discs and nerves that are not seen on X-ray images.
- Myelogram—Uses dye injected into the spinal canal to make the nerves more clearly visible on X-rays.
- Computed tomography scan (CT or CAT scan)—Uses a combination of X-rays and computer technology to produce horizontal (axial) images of the body. A CT scan shows detailed images of any part of the body including bones, muscles, fat and organs.
- Electromyography (EMG)—Measures muscle response or electrical activity in response to a nerve’s stimulation of the muscle. This test is useful to look for any problems with nerve or muscle function.
Cervical herniated discs are first treated with nonsurgical approaches like rest, modified activities, medications to relieve pain and inflammation, physical therapy and possibly stronger medications such as steroid injections. Symptoms of cervical ruptured disc normally improve over time. However, if the herniated disc is pressing on your spinal cord and creating severe problems that can't be resolved without surgery, anterior cervical discectomy with cervical fusion surgery should be considered to remove the problem disc and re-stabilize the spine.
Nonsurgical treatments for lumbar herniated discs usually consist of limited bed rest, back support and therapy. Most people suffering from a lumbar herniated disc do not need surgery. About 90 percent will recover within a month with nonsurgical treatments, and only 10 percent may eventually require surgery.
The majority of slipped discs heal naturally on their own or with the assistance of physical therapy. Anti-inflammatory medications can temporarily relieve pain and swelling in the meantime. If the herniation is severe and the pain does not subside or worsens over time, the herniated disc may require surgery.