What is a herniated disk?
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 disks, which act as shock absorbers. Each disk has a soft, gel-like center — called the nucleus pulposus — surrounded by a tough, fibrous outer layer called the annulus.
A herniated disk — also called a slipped disk or ruptured disk — 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 disk, resulting in pain.
Herniated disks most frequently occur in the lower part of the spine; however they can also occur in the cervical and thoracic spine. A herniated disk is one of the most common causes of neck, back and/or leg pain (sciatica) and neckache
How common are herniated disks?
Herniated disks are very common. They occur more often in people aged 35 to 55 years. They are more common in men than in women.
Symptoms and Causes
What are the symptoms of a herniated disk?
Herniated disks often produce no symptoms at all. Symptoms of a herniated disk in the lower 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 disk 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.
What causes a herniated disk?
A herniation occurs when the outer part of the disk, the annulus, becomes weak and tears. Several factors can contribute to disk-weakening, including
- Aging and degeneration.
- Excessive weight.
- A sudden strain from improper lifting or from twisting violently.
What complications are associated with a herniated disk?
Chronic (ongoing) back or leg pain and loss of control or sensation in the legs or feet are some complications of an untreated disk herniation.
Diagnosis and Tests
How is a herniated disk diagnosed?
Your healthcare provider will begin an evaluation with a complete physical examination and medical history, including a review of your symptoms. He or she might perform a neurological exam to test your muscle reflexes, sensation, and muscle strength.
The healthcare provider might use certain other diagnostic tests to confirm the diagnosis and to better evaluate the site and extent of the herniation. These tests might include:
- X-ray : X-rays use small doses of radiation to produce images of the body. An X-ray of the spine might be done to rule out other causes of the back or neck pain.
- MRI or CT scan: Magnetic resonance imaging (MRI) and computed tomography (CT) scans can show narrowing of the spinal canal caused by a herniation.
- Myelogram: This is an injection of dye into the spinal canal followed by a CT scan. A myelogram can help pinpoint the size and location of the herniation.
- EMG: An electromyelogram (EMG) involves placing small needles into various muscles and measuring electrical activity. The muscle's response, which indicates the degree of nerve activity, is measured. An EMG can help determine which nerve root or roots are being affected by the disk herniation.
Management and Treatment
How is a herniated disk treated?
Most herniated disks resolve on their own or with conservative treatment, which includes rest, anti-inflammatory medicine, and physical therapy. Some people find that ice packs or moist heat applied to the affected area provides some symptomatic relief of the pain and muscle spasms in the back. In cases that do not improve with conservative treatment, spinal injections or surgery might be needed.
- Medicine: Nonsteroidal anti-inflammatory drugs (NSAIDs) help to relieve pain, inflammation, and stiffness, allowing for increased mobility and exercise.
Common over-the-counter NSAIDs include aspirin, ibuprofen (Motrin®, Advil®), and naproxen (Naprosyn®, Aleve®). You may take medicines with food to avoid stomach irritation.
Muscle relaxants and various analgesics might be prescribed to relieve the discomfort associated with severe pain or muscle spasms in the initial treatment periods.
- Physical therapy: The goal of physical therapy is to improve core strength, flexibility and endurance to enable you to engage in your normal activities.
The exercises prescribed by your physical therapist can also help relieve pressure on your nerves, reducing the symptoms of pain and weakness. The exercise program often includes stretching exercises to improve flexibility of tight muscles and aerobic exercise — such as walking or using a stationary bike — to build endurance and improve circulation.
Other exercises might help to strengthen the muscles of your back, abdomen, and legs.
- Spinal injections — An injection of a cortisone-like medicine into the lower back might help reduce swelling and inflammation of the nerve roots, allowing for increased mobility. These injections are referred to as epidurals or nerve blocks.
- Surgery — Surgery might be needed for people who do not respond to conservative treatment, whose symptoms get progressively worse, or who experience progressive neurologic decline. Rarely, a large disk herniation might injure nerves to the bladder or bowel, which requires emergency surgery. The most common surgical options include microdiscectomy, laminectomy, or foraminotomy.
- Microdiscectomy — Microdiscectomy is a procedure used to remove fragments of a herniated disk, often using an operating microscope.
- Laminectomy — The part of the bone that curves around and covers the spinal cord (lamina) and the tissue that is causing pressure on the nerve or spinal cord are removed. This procedure is performed under general anesthesia. The hospital stay is one to two days. Complete recovery takes about six weeks.
Can anything be done to prevent a herniated disk?
It is not always possible to prevent a herniated disk, but there are steps you can take to reduce your risk:
- Use proper lifting techniques. Do not bend at the waist. Bend your knees while keeping your back straight and use your strong leg muscles to help you support the load.
- Maintain a healthy weight. Excess weight puts pressure on the lower back.
- Practice good posture when walking, sitting, standing, and sleeping. For example, stand up straight with your shoulders back, abdomen in, and the small of your back flat. Sit with your feet flat on the floor or elevated. Sleep on a firm mattress, and sleep on your side, not your stomach.
- Stretch often when sitting for long periods of time.
- Do not wear high-heeled shoes.
- Exercise regularly to keep the muscles of your back, legs, and stomach strong. Engage in regular aerobic exercise. Try to balance flexibility with strengthening in a regular exercise program.
- Stop smoking.
- Eat healthy, well-balanced meals.
Outlook / Prognosis
What is the outlook for people with herniated disks?
Most back and leg pain will get better gradually — usually within six weeks — by taking simple measures. In fact, most people with herniated disks respond to conservative treatment within six weeks and are able to return to their normal activities. Some will continue to have back pain even after treatment.