Disks are your spine's shock absorbers, flexible cushions that fit in between vertebrae. When you move your back, the disks absorb the pressure on your spine. They're incredibly strong, but they're subject to wear and tear. As you and your back age, the outer covering of these cushions can wear thin, especially if you strain your back. Eventually, the jelly-like center of one or more disks may start to ooze out. This is called a herniated or "slipped" disk. You don't have to be old to have a herniated disk. They usually happen to people in their 30s and 40s.
What can contribute to a herniated disk?
Sudden pressure, smoking, repetitive strenuous activities, improper lifting (such as twisting and turning while picking up something heavy) and carrying extra body weight that puts stress on the discs in the lower back can all help weaken disks in the lower back.
Do herniated disks always cause pain?
A herniated disk can be painful, especially if it presses against a nerve. But usually the condition is silent. Plenty of people who have herniated disks never know it -- it simply doesn't cause any pain. In fact, studies have found that roughly 22 to 40 percent of people without back pain have herniated disks.
Many people who suffer from back pain also have herniated disks, but the two problems aren't necessarily related. Many cases of back pain arise from sprained or strained muscles in the lower back, not leaking disks. According to a report in the New England Journal of Medicine, herniated disks account for only about 4 percent of cases of lower back pain.
What are the symptoms of a herniated disk?
You may feel pain that is especially severe after any sort of strain, including coughing or prolonged periods of sitting or standing. If the filling of a ruptured disk presses against a nerve, you may feel a sharp, shooting pain that runs from your lower back through your buttocks and down one of your legs. This type of pain is called sciatica.
Seek immediately medical attention if you notice signs of nerve damage such as numbness, tingling, and weakness in your legs, feet, or buttocks. Rarely, the disk may pinch the nerves that control bowel and bladder function, causing incontinence.
If pain, numbness and weakness have spread to one or both of your legs; you have a loss of bladder or bowel control or are unable to urinate; and/or you feel a loss of sensation in your inner thighs, back of the legs and areas around the rectum, go to the emergency room: you may have a compression of the spinal nerve roots, a problem that can require emergency surgery to relieve the pressure.
How are herniated disks diagnosed?
Your symptoms alone might be enough to make your doctor suspect a herniated disk, but it's all guesswork unless he or she takes a picture with an MRI (magnetic resonance image) or a CT (computed tomography). These tests can give your physician a clear view of your spine, leaky disks included.
An MRI is probably the best test, because it gives a clear view of the bones, the disks, and the nerve roots that may be damaged. Since herniated disks account for only a small percent of low back pain, however, doctors generally don't do an MRI unless a patient has both back pain and warning signs of a serious injury or disease.
In addition, these imaging tests have a major drawback: They can't prove that herniated disks (or any other common abnormalities) are actually causing your pain. Indeed, the pictures may just confuse the issue. If a patient suffers from a simple back sprain, a picture of a herniated disk could cause unnecessary anxiety or worse, unnecessary treatment.
Many experts now believe that high-tech images are overused for back pain. The New England Journal of Medicine report suggests that doctors should hold off on such tests for at least a month, unless they suspect an infection, cancer, or nerve damage. The pain often gets better on its own, without treatment, and disk abnormalities that the doctor sees on the MRI may not be the cause of the pain.
What can I do to ease the pain?
Not only are disks durable, they're also very resilient. If you rest and take good care of your back, there's a good chance your disk will get better without medical treatment. According to a report from the Mayo Clinic, most herniated disks will take four to six weeks to significantly improve, and many manage to return to normal within a couple of months.
Taking the strain off your back is the first step in the healing process. You may need to start by taking it easy for a couple of days. Don't lift heavy objects, bend repeatedly, sit for long periods, or do anything else that might aggravate your back. But you don't want to become a couch potato, either. Regular activity will help strengthen your back and promote healing. Your doctor or physical therapist can recommend specific exercises to speed the healing process and prevent future injuries.
While you're waiting for your back to heal, you can take over-the-counter pain relievers such as aspirin or ibuprofen. For extra relief, try putting a cold compress on the aching spot for 15 minutes at a time, four times a day. If you're still in pain, your doctor may prescribe stronger painkillers. Injections of corticosteroids -- medications that calm inflammation -- are another option for pain control in selected cases. In especially severe cases, your doctor may also try a nerve block (regional anesthesia).
Some people who suffer from back pain have tried transcutaneous electrical nerve stimulation (TENS). In TENS, a physical therapist uses a battery to send very modest electrical current into the muscle, thought to stimulate the body to release endorphins, the body's natural painkillers. Controlled studies have shown conflicting data as to the benefit of this practice.
Some find relief from acupuncture. Studies have shown conflicting results, but a systematic review by the Cochrane Collaboration, which evaluates evidence for medical and complementary treatments, found that acupuncture was a useful added treatment for chronic low back pain. Ask your doctor if acupuncture is a good option for you.
When is surgery necessary?
Most people with herniated disks never need to seek an operation. For a small minority, however, surgery is the only option for relief. If signs of nerve damage -- numbness, tingling, and weakness -- grow steadily worse, you may need an operation right away. Likewise, a herniated disk that interferes with the bowel and bladder is a medical emergency and requires immediate treatment.
For other patients, doctors take a wait-and-see approach. If your sciatica (pain shooting from your lower back down to your leg) lingers for six weeks or more despite your self-care efforts, you and your doctor may want to start thinking about getting an MRI and evaluating the need for surgery.
How does a surgeon treat a herniated disk?
The traditional surgical treatment for herniated disk is a diskectomy. In this procedure, a surgeon will cut away the portion of the disk over the spinal canal that is pressing against the nerve. At the same time, a surgeon may trim some of the bone from the backside of the vertebrae to relieve pressure on the nerves, a procedure called a laminectomy.
In recent years, surgeons have developed a new twist on this approach. The troublesome part of the disk can be removed through a tiny incision with the use of a special microscope, a procedure called a microdiskectomy. This technique seems to be just as effective as a standard diskectomy, but patients tend to recover more quickly. According to the Mayo Clinic, success rates for both diskectomy and microdiskectomy -- measured by pain relief and patient satisfaction -- reach about 80 to 90 percent.
Having a herniated disk sounds serious -- but it's only rarely a true emergency. With care and time, the pain will usually disappear entirely.
Furlan AD, van Tulder MW, Cherkin D, Tsukayama H, Lao L, Koes BW, Berman BM. Acupuncture and dry-needling for low back pain. The Cochrane Database of Systematic Reviews Issue 11.
American Academy of Orthopaedic Surgeons. Herniated disk.
Herniated Disks. Mayo Clinic.
Brinkhaus B., et al. Acupuncture in patients with chronic low back pain: a randomized controlled trial. Archives of Internal Medicine. 166(4):450-7.
Asch, HL et al. Prospective multiple outcomes study of outpatient lumbar microdiscectomy: should 75 to 80% success rates be the norm? Journal of Neurosurgery 96 (1 suppl.) 34-44
Carlsson, C.P., et al. Acupuncture for chronic low back pain: a randomized placebo-controlled study with long-term follow-up. Clinical Journal of Pain 17; (4):296-305