The spine is made up of cylindrical bones called vertebrae. Between the bones of the spine are small discs made of a thick layer of cartilage on the outside and a soft, jelly-like material on the inside. The discs act to absorb shocks caused when the spine moves, and they allow the spine to bend.
The spinal cord is a bundle of nerves running through the canal within the spinal column. It carries messages to and from the brain via nerve roots that branch out to the body along the length of the spinal cord. The nerves exit the spine through small openings on each side; these are called foramens (singular foramen; foramina is also used for the plural), after the Latin word for "window."
If a foramen becomes narrowed by arthritis or a bulging disc, pressure on the nerve can cause numbness and pain, and even muscle weakness if severe enough. A herniated, prolapsed, or ruptured disc happens when the inner material bulges or bursts through the outer lining of cartilage and puts pressure on or damages the spinal nerves or the spinal cord.
Herniated discs can occur in any part of the spine, but they are most common in the neck (cervical spine) and lower back (lumbar section of the spine). Herniated discs are more common in people between 30 and 40 years old, but they can occur at any age. Studies have shown that even some teenagers can be affected.
As we age, the discs in the spine become less flexible, which increases the risk of injury. Other things that can increase the risk of a herniated disc include an injury such as a fall, repeated straining, improper lifting, excessive body weight, and smoking.
When a disc is herniated, the soft material inside the disc comes through the outer lining of cartilage. Normally there is some space between the discs and the spinal column. But, when the herniated disc presses on a spinal nerve, this leads to symptoms of pain, numbness, and weakness.
Symptoms and Complications
Not all people with a herniated disc have symptoms. But when a herniated disc presses on spinal nerves, symptoms can include pain, loss of feeling, tingling, or muscle weakness. The amount of pressure the herniated disc puts on the spinal nerves determines how bad the symptoms will be. Coughing, laughing, sneezing, urinating, or straining while defecating make the pain of a herniated disc worse.
Most herniated discs are in the lower back and cause back and leg pain. Intense pain that radiates down from the disc through the buttocks and down the leg to the foot is called sciatica.
Intense pain below the knee is usually a sign of a herniated disc, since other back conditions don't usually cause pain below the knee. A herniated disc in the lower back can cause weakness in the legs and trouble lifting the front of your foot off the ground.
Herniated discs also occur in the neck (cervical spine). They can cause pain in one arm, beginning with the armpit and upper shoulder blade and travelling down the arm to one or two fingers. The pain can also be felt in the upper middle back and can be mistaken for other conditions. Arm muscles can weaken, making it hard to move the fingers.
Pressure on nerves at the bottom of the spinal cord can cause loss of bladder or bowel control, both of which are signs of very severe nerve pressure. Those symptoms, or loss of muscle function in the leg, are signs of a medical emergency, so get immediate medical attention if you experience these symptoms. The sooner you are seen, the more chance there can be some recovery of function.
Rarely, a ruptured disc in the neck can cause complete paralysis.
Making the Diagnosis
Your doctor will perform a physical exam and ask you about your symptoms. Your doctor may check your spine and may test your coordination, muscle strength, and reflexes, and your ability to feel sensations. In some cases, your doctor will be able to make a diagnosis based on your symptoms and the results of the physical exam.
However, your doctor may order other tests, such as spinal X-rays or MRI (magnetic resonance imaging) and CAT (computerized axial tomography) scans, to confirm the diagnosis or to check for other causes of your symptoms. The MRI is most definitive.
However, the doctor must interpret and use the results of these tests carefully. The tests can show apparent severe disease in people with no signs or symptoms, and they can show that nothing is wrong (i.e., negative test results) in people who have the condition based on their symptoms and physical exam. Treatment must be based on evaluation of the whole picture and the whole patient, not just on an MRI or other single finding.
Treatment and Prevention
The treatment plan you and your doctor decide on for a herniated disc will depend on several factors, including the severity of your symptoms, your activity level, and how your lifestyle is affected.
The treatment of a herniated disc can include non-surgical and surgical options. In most cases treatment starts conservatively with non-surgical options, which are effective for more than 90% of people. If non-surgical options are not effective, then surgical options are considered. For people whose symptoms are progressively worsening or who experience loss of bladder and bowel control, surgical options will be considered much earlier.
Non-surgical options for a herniated disc include trying to stay active, unless pain is severe. If you do need bed rest, your doctor will likely suggest that you limit this to 1 or 2 days.
Anything longer than this may cause muscles to weaken and worsen your symptoms. Avoid activities that aggravate your symptoms, such as bending, lifting, or sitting for long periods of time.
Using a firm mattress while sleeping may help. It may also help to put a pillow under the waist and another under the shoulder if you sleep on your side, or putting a pillow under your knees if you sleep on your back.
Your doctor may suggest medications such as acetaminophen* or nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., ibuprofen) to help relieve pain. If the pain is severe, your doctor may prescribe opioid (also called narcotic) pain medications such as codeine or oxycodone, muscle relaxants, or other medications that help with nerve pain (e.g., amitriptyline, gabapentin).
Corticosteroids by mouth or by injection may be prescribed for severe and persistent pain. Occasionally, injecting lidocaine and corticosteroids into a very painful spasmodic part of the back muscle can give temporary relief.
Cold compresses or ice can help with pain when applied several times a day for no more than 20 minutes. Heat application may also help.
To prevent recurrences, it is very important to lose excess weight, particularly in the abdomen, and do exercises when you are feeling better to improve posture (strengthening abdominal muscles and stretching back muscles).
The vast majority of cases are resolved with conservative treatment: Being active within sensible limits, exercising, taking over-the-counter pain relievers, controlling your weight, and having heat and cold therapy.
Spinal manipulation is a commonly used conservative treatment by various health care practitioners, such as chiropractors and physiotherapists. Every treatment comes with some risk, however, the chances of spinal manipulation worsening the herniation appears to be low.
Other methods such as ultrasound, TENS (transcutaneous electrical nerve stimulation, which is using an electrical current to stimulate the nerves), and massage therapy may sometimes provide relief by helping to ease muscle spasm, which is a secondary effect of disc disease. Acupuncture has shown mixed results. If it is used, to prevent transmitting infection it is extremely important that needles not be reused.
A qualified health care professional like a chiropractor, physiotherapist, or a medical doctor can show you exercises that will help strengthen the spinal muscles and reduce the risk of injury to the disc and spinal nerves. Supervision by a healthcare professional may be helpful if you are not sure you can do it on your own.
Changing sitting positions can also help. Put the feet up on a low stool to flatten the back against the back of the chair, or adjust the chair so it tilts forward. A mattress with good, firm support and proper pillows for sleep is also very important.
Back braces are usually of little help, though many people use them anyway. They are not a substitute for other care.
Surgery isn't usually considered unless you develop severe pain or nerve damage that gets steadily worse. Surgery is called for when there is such severe damage to nerve or spinal cord that relief is necessary to preserve or to try to restore some function (such damage may not be reversible). It is also considered when all other pain relief methods fail, and people are unwilling or unable to give it more time and feel that the benefits of surgery outweigh the risks.
If you have loss of bladder or bowel control, you may need surgery right away. When possible, surgery to remove the ruptured disc is done through a very small incision under general anesthesia, but in other cases, major surgery is required.
Traction and a supportive neck collar can help a herniated disc in the cervical spine. During traction, a machine gently pulls the spine to relieve the pressure on it. A doctor or physiotherapist needs to show the person how to safely use the traction equipment. Traction therapy may be recommended for use at home. It must be used properly to avoid doing harm.
Studies have shown that 2 years or less of conservative treatment for back pain in which there is no significant nerve damage works just as well as surgery, physical therapy, and any of the other treatments described here.
Do the following to help prevent a recurrence of a herniated disc:
- Do exercises that strengthen the abdominal and back muscles.
- Maintain good posture (stand up straight, sit straight, lift things with the back straight).
- When sitting, sit with your backside against the back of the seat, do not slide forward, and use a foot rest.
- Bend the knees and hips when lifting something and keep the back straight.
- Hold an object close to the body when carrying it.
- Avoid wearing high-heeled shoes.
- Keep at a healthy weight with a trim abdomen.
- Don't smoke.