A herniated disc is a condition in which part of an intervertebral disc bulges through its protective covering and may press on a nerve. Pressure on the nerve can cause pain that begins in the back or neck and often extends down a leg (causing sciatica) or an arm.

A herniated disc sometimes follows a single, traumatic injury. However, in most cases it is due to gradual, aging–related deterioration, such as degenerative disc disease or spinal arthritis.

Most herniated discs begin to heal after a short period of rest and home-based remedies such as anti-inflammatory drugs, cold therapy and heat therapy. In some cases pain may linger and require professional treatment, such as physical therapy or nonsurgical spinal decompression. In rare cases, spinal surgery is recommended. Herniated discs that result in sudden muscle weakness or loss of bowel or bladder control are potentially serious conditions that may require immediate emergency surgery.

Disc degeneration or herniation in itself may not be painful at all. Research has shown that young healthy adults in their 30s without any complaint of back pain may have evidence of herniated discs on MRI (magnetic resonance imaging).

A herniated disc – also known as a slipped, bulging, protruding or ruptured disc – occurs when the cartilage (tough, elastic, fibrous connective tissue) of an intervertebral disc bulges out and in many cases compresses a spinal nerve root. This can result in pain that ranges from mild to severe in intensity.

The severity of pain does not necessarily correspond to the extent of damage to the disc. A large amount of damage sometimes will cause little pain, whereas a small amount of damage may cause excruciating pain.

The back is made up of a network of bones, ligaments, muscles and nerves that work together to balance and bear the weight of the body. The spine (vertebral column) is made up of 33 bones (vertebrae), some of them fused, held together by zygapophysial (facet) joints and by fibrous bands (ligaments). There are seven cervical vertebrae in the neck and 12 thoracic vertebrae in the middle of the back. The five large lumbar vertebrae of the lower back carry most of the body’s weight. Below the lumbar vertebrae in the pelvis are the wedge-like sacrum, made from five fused vertebrae, and the coccyx (tailbone).

The spine supports the weight of the head and houses and protects the spinal cord. The spinal cord is part of the central nervous system and extends from the base of the skull to the lower back. Two nerves extend out at each vertebral level. There are 31 pairs of these spinal nerves in the back and neck. In the part of the back where the spinal cord ends, a group of nerves (the cauda equina) continue down the spinal canal.

Most vertebrae are separated by an intervertebral disc, which acts like a “shock absorber” that prevents the vertebrae from hitting each other during activities such as walking, running or jumping. Each disc is made up of an outer ring of tough, fibrous tissue (annulus fibrosus) that has a jelly–like substance in the center (nucleus pulposus). The interior of each intervertebral disc is mostly composed of water (80 percent) and has no blood supply of its own. The nucleus pulposus hardens with age, beginning in a person’s 30s.

Muscles extend up and down the back to support the spine, contracting or relaxing to help a person stand, twist, bend or stretch. Tendons connect muscles to bones. The muscles of the abdomen and trunk also support, protect and move the spine.

Intervertebral discs are under constant pressure. Herniated discs may result from injury or disc degeneration due to aging or disease, such as degenerative disc disease or spondylosis (spinal osteoarthritis).

Herniated discs occur most often in the lower (lumbar) vertebrae. This a common cause of sciatica, in which the sciatic nerve serving the leg is compressed, often causing tingling, numbness, pain or weakness (paresthesia) down the leg and into the foot. The second most common site of herniated discs, the cervical (neck) area, can cause paresthesia in the shoulder and arm. Both of these complications are examples of a pinched nerve.

In some cases, cartilage that is pushed into the spinal canal may compress the bundle of lumbar and sacral nerve roots at the end of the cauda equina. This condition, cauda equina syndrome, demands immediate medical attention. Left untreated, cauda equina syndrome can cause permanent neurological damage.

Herniated discs are most likely to affect people in their 30s to 50s, as the discs become flatter and begin to dry out with age. In some cases, the pain caused by a herniated disc can make it difficult to perform routine tasks, such as sitting, standing, working or playing.

There are several options for treating this pain, ranging from medications to surgery. In most cases, the portion of a herniated disc that protrudes and pressures the nerve tends to shrink within six months to a year after injury, relieving symptoms.

Although a herniated disc sometimes follows a single traumatic injury, it is more often the result of gradual, aging-related degeneration of the disc. By the age of 30, intervertebral discs (discs that serve as cushions between the vertebrae) begin to flatten, deteriorate, lose water content, thin out and become brittle.

Eventually, this deterioration, known as degenerative disc disease, may cause the nucleus pulposus in the center of the disc to swell or bulge. The pressure of this bulging may eventually create tiny tears in the tough, fibrous outer covering of the disc. If the nucleus pulposus in the center of the disc pokes through these tears, it is known as a herniation or rupture. In some cases, the nucleus pulposus may break through far enough to cause pressure on and irritate a nerve and result in a pinched nerve. Pain in the back, neck or a limb may result.

Sometimes, a herniated disc will cause material to compress the bundle of lumbar and sacral nerve roots at the end of the spinal cord known as the cauda equina. This condition is called cauda equina syndrome, and it may cause permanent neurological damage if left untreated.

Herniated discs occur most commonly in people in their 30s to 50s. They are most likely to affect middle-aged men engaged in strenuous activity. Having a congenital (present at birth) or acquired condition that affects the size of the spinal canal, such as spinal stenosis, raises the risk for developing nerve compression from a herniated disc.

Other conditions that can promote disc herniation include:

• Spondylosis. Spinal osteoarthritis, usually in the cervical or lumbar spine, often involving osteophytes (bone spurs).
  
  
• Osteoporosis. A common condition in which the bones lose density. Osteoporosis can lead to vertebral and other fractures and contribute to disc degeneration.
  
  

Herniated discs cannot always be prevented. However, good posture and ergonomics, such as proper lifting techniques, and other preventive measures can lower the risk of a herniated disc. In addition, not all herniated discs cause pain.

Patients may experience a single occurrence or several episodes of back pain or neck pain before an intervertebral disc bulges or ruptures. Once a rupture occurs, it is likely to be followed by sharp or throbbing pain that can cause mild to severe discomfort in the back or neck and shooting pain down a limb. Discs that are damaged in the middle or lower part of the back may cause numbness, tingling or weakness (paresthesia) in the buttocks, legs or feet. Injured cervical (neck) discs may cause these sensations down the shoulder and arm, sometimes to the hand and fingers.

Activities that pressure a nerve can cause flare–ups of pain in people with herniated discs. For example, shooting pain may occur during coughing, sneezing or straining. Pain also is often worse following prolonged sitting or standing. In most cases, just one limb is affected. However, pain may affect both legs or both arms when herniation occurs in the midline of the spine and compresses nerves on both sides of the body.

Patients with herniated discs may find that the pain interferes with nearly all aspects of their lives. The pain can make it difficult to sit or bend. Many patients experience sharp sciatica pain that begins in the back and radiates down into the legs. Although herniated discs are extremely unlikely to result in paralysis, the back and limb pain is often intense enough to severely affect a patient’s quality of life.

Certain symptoms associated with herniated discs indicate very serious conditions warranting immediate medical care. Patients should see a physician promptly if they experience either of the following:

• Significant or progressive muscle weakness. Patients who suddenly find themselves unable to lift their foot, stand on their toes or use their arm may have a damaged nerve that is significantly worsening. This may require surgery.
  
  
• Loss of bowel or bladder control (incontinence). Either of these symptoms – which are sometimes accompanied by numbness in the saddle (perianal) area near the anus – may indicate that the nerves that control the bladder or bowel have been compressed. In such cases, the nerves may need to be surgically decompressed. In addition, incontinence may be a symptom of cauda equina syndrome, which requires immediate medical attention to prevent permanent neurological damage.

In diagnosing a herniated disc, a physician will review a medical history and perform a physical examination. In addition, the physician may perform a straight–leg–raising test in which the patient lies flat and the doctor lifts each leg up. If the patient experiences pain in the back at certain angles, it may indicate a herniated disc.

A physician may also order an imaging test to help reveal the extent of damage to a disc and to rule out other possible sources for the pain, such as a spinal tumor or circulatory problems. Imaging tests that may be performed include x-ray, MRI  (magnetic resonance imaging) or CAT scan (computed axial tomography).

If noninvasive tests indicate a disc problem, the physician may order a minimally invasive imaging test to get information in greater detail. Discography is a type of x-ray involving an injection of contrast medium (dye) into the injured disc. In myelography, the dye is injected into the spinal canal.

Nerve tests such as electromyography (EMG) may also be performed. This can help detect signs of nerve damage resulting from a disc herniation, and can determine which nerve roots are involved. EMG uses electrodes placed on the skin or needles inserted into muscle to help determine function of nerves and muscles. It is often performed in conduction with nerve conduction velocity (NCV) studies, which use electrodes to measure the speed of nerve impulses.

Despite these tests, in many cases it may be difficult to determine whether or not a herniated disc is the source of a patient’s back pain. About one–third of all adults age 30 and older show signs of intervertebral disc abnormality due to natural degeneration, but in most cases this damage does not result in pain. Discography is considered one of the most useful tests to diagnose discogenic pain (pain originating from herniated disc).

There are a number of potential treatments for herniated discs. The aim is to control pain, maintain activity and muscle tone and prevent further injury. Except in extreme cases, physicians will not recommend surgery as an initial form of treatment. Instead, other therapies will be used to treat the problem.

After an intervertebral disc herniates, the portion that protrudes and pressures the nerve tends to shrink over time. In many cases, partial or complete shrinkage occurs within six months to a year after injury. The vast majority of herniated discs are treated successfully without resorting to surgery.

The goal of nonsurgical treatments of herniated discs is to reduce irritation to the disc and the nerves. This will give the body time to heal itself. Such pain management treatments include:

• Rest or decreased activity. In many cases, a day or two of rest in a bed with a firm mattress will relieve a patient’s pain. Other patients are more comfortable lying with their back on the floor with hips and knees bent and legs elevated.

However, patients should not rest for more than two days unless pain is so severe that it cannot be relieved in any other way. Too much rest prohibits patients from maintaining the muscle tone they need to recover. It has been seen in studies that people tend to have less chronic back pain if they return to their normal regular activity (not involving heavy weight lifting) early.

• Medication. Over–the–counter drugs such as nonsteroidal anti–inflammatory drugs (NSAIDs) can help relieve inflammation and pain. Analgesic medications such as acetaminophen relieve pain but do not reduce inflammation.
  
  In cases of more severe pain, prescription narcotic pain medications (opioids) may be suggested. Injection or oral ingestion of corticosteroids may become necessary if all other medications fail to relieve pain. These drugs help suppress inflammation. When injected, they are given as an epidural steroid injection into the area around the spinal nerves, providing quick and substantial relief for many patients. However, these medications must be used sparingly and under a physician’s close  supervision because they can have significant side effects.

Other medications that may help relieve pain brought on by herniated discs include:

TNF (tumor necrosis factor) inhibitors, a class of anti-inflammatory drugs used to treat rheumatoid arthritis, psoriatic arthritis and inflammatory bowel disease, are being studied as a form of biologic therapy to treat herniated discs.

• Cold therapy or heat therapy. Cold packs (cryotherapy) can be applied to painful areas for 15 to 20 minutes at least four times daily. It is recommended that ice be wrapped in a towel or used in a cold pack – ice should not be applied directly to the skin. At least 15 minutes should separate sessions of therapy with ice. Heat therapy (thermotherapy) is also sometimes effective in treating pain associated with herniated discs. Methods of treatment include warm packs, heat lamps or heating pads kept on the lowest setting. Patients who continue to experience pain can alternate cold and warm therapy.
  
  
• Electrical stimulation. Transcutaneous electrical nerve stimulation (TENS) is a technique in which small doses of electrical current are delivered along the nerve pathway. It is believed that this treatment stimulates the release of pain–inhibiting molecules (endorphins) or blocks pain fibers that carry pain impulses.
  
  
• Physical therapy. In many cases, treatment will involve physical therapy that includes exercises to help correct posture, strengthen the muscles supporting the back and improve flexibility. A program called dynamic lumbar stabilization focuses on exercises that coordinate the use of both the abdominal and back muscles in a balanced spine posture. Physical therapy can help the patient both recover from the herniated disc and lower the risk of suffering a similar injury in the future.
  
  Nonsurgical spinal decompression therapy. The U.S. Food and Drug Administration (FDA) has approved systems in which the patient lies on a special mechanical table designed to relieve pressure on the discs. A patient may have sessions of up to an hour most days of the week for several weeks.
  
  Spinal orthoses (back braces). The FDA has approved a wide range of orthoses to relieve pressure on the intervertebral discs, including flexible, semi-rigid and rigid models.
  
  
• Occupational therapy. A physician may recommend occupational therapy if a patient has difficulty performing daily tasks and could benefit from instruction or equipment to adapt.

Some patients will also seek complementary and alternative approaches to treating their back pain, the most popular of which include:

• Acupuncture. Although this therapy is not used to treat herniated discs, it may help relieve back pain. It involves insertion of hair–thin needles under the skin. Patients feel little or no pain and the needles usually remain in place for 15 to 30 minutes a session over several sessions.
  
  
• Chiropractic treatment. This therapy involves spinal adjustment (manipulation) to treat restricted spinal mobility by restoring spinal movement. According to proponents, this improves function and decreases pain. However, most physicians do not recommend chiropractic care to treat a herniated disc, except when methods such as FDA-approved spinal decompression therapy are used. Other methods may sometimes be harmful in an unstable spine.

In some cases, nonsurgical techniques are not sufficient to effectively treat back pain, leg pain and neck pain associated with a herniated disc. Unless there is a need for immediate surgery – indicated by symptoms such as progressive muscle weakness or lack of bladder control – most physicians will urge patients to wait at least six to 12 weeks after the onset of unrelieved pain before considering surgery as an option.

Spinal surgery may be performed to keep the herniated disc from pressing on and irritating nerves, thus relieving pain. Open decompression procedures are one type of surgery used to treat herniated discs. They include:

• Discectomy. Removal of all or part of a disc to relieve pressure on a nerve. The herniated portion of the disc and any pieces that have broken loose are removed. When possible, just the fragment of the disc that is pinching the nerve is removed. In many cases, this is performed in tandem with a procedure called a partial facetectomy, which involves removing a small part of an area of the spine called the facet joint that may be compressing the nerve.
  
  
• Laminotomy and laminectomy. Both procedures involve removing a small amount of the back part of the bone over the spinal canal (lamina). A portion of the lamina is removed in a laminotomy, whereas the entire lamina is removed during a laminectomy. These procedures are often performed in conjunction with a discectomy.
  
  
• Microdiscectomy. Similar to a standard discectomy except that the procedure is performed through a small incision while the surgeon looks through a microscope.

Minimally invasive procedures are also used to treat herniated discs. They have the advantage of reducing the risk of complications and the need for a long recovery period, but have certain drawbacks. These procedures include:

• Endoscopic procedures (arthroscopy). Allow parts of the disc to be removed from between vertebrae with a mechanical device that fits into a large needle. Percutaneous (by way of the skin) discectomy involves use of continuous real-time x-ray (fluoroscopy). However, because endoscopic procedures are done through a smaller incision, the surgeon is unable to see the nerve root and may not be able to tell if the correct part of the disc has been removed. There has been lot of research into percutaneous decompression of herniated discs, but data are still preliminary.
  
  Intradiscal electrothermal therapy (IDET). In this form of electrical therapy, a wire is placed into an injured intervertebral disc, then electrically heated to seal and toughen the tissue.
  
  
• Chemonucleolysis. An enzyme (protein that acts as a catalyst for biochemical reactions) called a chymopapain is injected into the disc to dissolve the protruding disc and reduce pressure on the nearby nerve. However, chemonucleolysis generally is not used in the United States because of the risk of neurologic complications and allergic reactions to the enzyme.

In rare cases, vertebral fusion may be used to treat herniated discs. The procedure permanently connects two or more vertebrae to improve stability, correct a deformity or treat pain. Small pieces of extra bone are used to fill the space between two vertebrae and fuse the spin. The disc is removed first if the front of the spine is fused. Spinal fusion eliminates some spinal flexibility, which can be beneficial if movement between spinal segments is the source of a patient’s pain. However, most physicians do not recommend this procedure for a herniated disc.

Once a herniated disc has been successfully treated with surgery, the patient may undergo physical therapy.

The recent 11-state Spine Patient Outcomes Research Trial (SPORT) compared discectomy to nonsurgical treatment of herniated discs. It found that patients in both treatment groups showed comparable improvement over two years, with the surgery group having only a slight edge.

Exercises may be helpful in preventing pain associated with herniated discs. Stretching and strength training can make back and abdominal muscles stronger to ease pressure on the intervertebral discs. Patients should not undertake any exercise program without first consulting a physician.

Good posture and ergonomics can also relieve the pressure on the back. When lifting heavy objects, bend at the knees and hips and keep the back straight. Hold objects close to the body while carrying them. Other tips include:

• When standing for long periods of time, put one foot on a stool or box to relieve pressure on the back.
  
  
• When sitting for long periods of time, put feet on a stool so knees are slightly higher than hips and get up and walk around periodically.
  
  
• Maintain proper body weight. Excessive weight can increase the load on the lower back, increasing the risk of a herniated disc as well as other medical problems.
  
  
• Do not wear high-heeled shoes.
  
  
• Do not sleep on the stomach.

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following back questions about herniated discs:

1. How does a herniated disc cause me back pain?
   
   
2. Do some symptoms indicate I may have more serious condition than others?
   
   
3. What else could be causing my symptoms?
   
   
4. What diagnostic tests might I need to undergo, and what do they involve?
   
   
5. What do my test results show?
   
   
6. Is my herniated disc related to a pinched nerve, sciatica, degenerative disc disease or some other condition?
   
   
7. What are my treatment options?
   
   
8. Are there treatments I can use at home?
   
   
9. How long should it take before my pain subsides?
   
   
10. If noninvasive treatments fail, will I need to have surgery?
    
    
11. Are there things I can do to prevent further injury or new injuries?