LOW BACK PAIN CAUSES — Low back pain can have many causes. However, most people (>85 percent) have “nonspecific low back pain”, which is not caused by a specific disease or abnormality in the spine. Many people attribute their back pain to a degenerating disc or arthritis, although problems in muscles or ligaments may be equally responsible (figure 2).
Rarely, back pain is caused by a potentially serious spinal condition, such as infection, fracture, or tumor, or a disorder called cauda equina syndrome, which causes weakness and bowel or bladder dysfunction as well as back pain. Back pain that is associated with leg pain can be due to a herniated disc or spinal stenosis (see ‘Lumbar spinal stenosis’ below).
Degenerative disc disease — Wear and tear can lead to degenerative disc disease, or the breakdown of the spinal discs, with small cracks and tears and/or loss of fluid in the discs. This can lead to other changes including the formation of bone spurs. Calling this condition a “disease” is somewhat misleading because these changes occur with normal aging and frequently cause no symptoms. In fact, many people have degenerative disc disease seen on x-rays or other imaging studies but have no pain or other symptoms.
Facet joint arthropathy — Facet joint arthropathy refers to arthritis in the joints connecting the vertebrae to one another (facet joints). This can lead to bone spurs around the joint and may cause low back pain. However, like degenerative disc disease, facet joint arthropathy is very common with aging and many people have no symptoms.
Spondylolisthesis — Spondylolisthesis is a condition in which one of the vertebrae of the lower spine slips forward in relation to another. Spondylolisthesis is usually caused by stress on the joints of the lower back and may be associated with facet joint arthropathy. Although this condition can cause low back pain and sciatica, sometimes it causes no symptoms at all and is diagnosed with an x-ray done for another reason.
Herniated disc — Too much wear and tear on spinal discs can lead to herniation of a disc, in which the outer covering is weakened or torn, and the soft inner tissue extrudes (a “slipped disc”). Herniated discs can cause leg pain or weakness if the disc pinches a nerve root (figure 3). However, herniated discs are frequently seen on x-rays, even in people with no low back pain. Herniated discs usually heal over time because the body breaks down the excess disc material and water within the disc is absorbed, relieving pressure or irritation on the nerve.
A bulging disc is more common than a herniated disc and is seen in half of people who have no back pain. A bulging disc usually causes no symptoms, although occasionally it can cause sciatica (see’Sciatica’ below).
Lumbar spinal stenosis — Spinal stenosis is a condition in which the vertebral canal (the open space inside the vertebrae) is narrowed. This is often caused by inflammation due to one or more damaged discs, and is particularly common in older patients. Spinal stenosis can cause neurogenic claudication (see ‘Neurogenic claudication’ below). However, like herniated discs, spinal stenosis can be seen in people with no symptoms.
Less common causes of low back pain — Rarely, low back pain is caused by a serious spinal condition, such as an infection, tumor, or a disorder called cauda equina syndrome, which causes weakness and bowel or bladder dysfunction as well as low back pain. Other potential causes include spinal compression fractures, in which one or more vertebrae become fractured as a result of weakening and thinning of the vertebrae due to osteoporosis.
In younger people, low back pain with morning stiffness can be associated with an inflammatory condition called ankylosing spondylitis. (See “Patient information: Ankylosing spondylitis and spondyloarthritis”.)
Back pain and work — Factors that may contribute to low back pain at work include poor posture while sitting or standing, sitting or standing for long periods of time, driving long distances, improper lifting techniques, frequent lifting, or lifting excessively heavy loads. Low back pain is as common among clerical workers who sit for prolonged periods and in people whose jobs require heavy lifting
Psychological factors in the workplace can contribute to low back pain. These include stress, job dissatisfaction, boredom, tension, as well as how the body responds to everyday physical demands. Workplace stress can be eased with counseling; a number of techniques are available. Resolving these psychological factors improves a person’s chances of recovering from low back pain.
LOW BACK PAIN SYMPTOMS
Radiculopathy — A common feature of low back pain is radiculopathy, which occurs when a nerve root is irritated by a protruding disc or arthritis of the spine. Radiculopathies usually cause radiating pain, numbness, tingling or muscle weakness in the specific areas related to the affected nerve root. Most people with these conditions improve with limited or no treatment, described below (see ‘Low back pain treatment’ below).
Sciatica — Sciatica refers to the most common symptom of radiculopathy. It is a pain that occurs when one of the five spinal nerve roots, which are branches of the sciatic nerve, is irritated, causing a sharp or burning pain that extends down the back or side of the thigh, usually to the foot or ankle. You may also feel numbness or tingling. If a disc is herniated, sciatic pain often increases with coughing, sneezing, or bearing down.
Neurogenic claudication — Neurogenic claudication is a type of pain that runs down the back to the buttocks, thighs, and lower legs, often involving both sides of the body. This may cause limping and weakness in the legs. Pain usually gets worse when extending the lower spine (eg, when standing or walking), and gets better when flexing the spine by sitting, stooping, or leaning forward.
When to seek help — Most people with low back pain should be managed by a primary care or family medicine provider. If low back pain is caused by a serious condition, a neurosurgeon or orthopedist who specializes in back surgery is usually recommended. People who have any of the following should contact their healthcare provider for advice:
- If you are 70 years or older with new back pain
- Pain that does not go away, even at night or when lying down.
- Weakness in one or both legs or problems with bladder, bowel, or sexual function can be signs of cauda equina syndrome, arising from compression of the nerve bundle at the base of the spine. These symptoms should be evaluated as soon as possible.
- If you have back pain accompanied by unexplained fever or weight loss
- If you have a history of cancer, a weakened immune system, osteoporosis, or have used corticosteroids (eg, prednisone) for a prolonged period of time
- If the back pain is a result of falling or an accident, especially if you are older than 50 years.
- If pain spreads into the lower leg, particularly if accompanied by weakness of the leg.
- If back pain does not improve within four weeks.
LOW BACK PAIN TESTS — The vast majority of people with low back pain improve within 4 to 6 weeks without treatment or with simple measures that can be performed at home. It is not usually necessary to consult a healthcare provider if the pain improves . (See “Diagnostic testing for low back pain”.)
Imaging tests — Imaging tests, including plain x-rays, CT (computed tomography) scanning, or an MRI (magnetic resonance imaging), may be recommended for people with certain conditions .
X-rays — X-rays may be recommended for selected people who have risk factors or signs of infection, cancer, or vertebral compression fracture related to osteoporosis (see ‘When to seek help’ above).
However, x-rays do not usually show enough detail to diagnose a herniated disc or spinal stenosis. Other common conditions, such as degenerative disc disease, facet joint arthropathy, and disc space narrowing, are seen so frequently in people without low back pain that it is usually not helpful to get x-rays to look for these, especially since their presence does not change treatment in the first 4 to 6 weeks.
CT and MRI — CT scanning and MRI provide detailed images of the soft tissues and bony structures of the back. A CT or MRI is usually necessary to diagnose a herniated disc or spinal stenosis. One of these tests may be recommended if surgery is being considered or if low back pain persists for more than 4 to 6 weeks and the cause of pain cannot be determined with other methods.
However, most people with low back pain do not require a CT or MRI. Disc and spine abnormalities are common among people without low back pain. In fact, a herniated disc is seen on MRI or CT in 25 percent of people without low back pain.
LOW BACK PAIN TREATMENT — Unless low back pain is caused by a serious medical condition, a rapid recovery is expected, even if there is a bulging disc. The body breaks down bulging discs, taking pressure off the nerve. Care of an attack of low back pain includes several simple elements. (See “Treatment of acute low back pain”.)
Remaining active — Many people are afraid that they will hurt their back further or delay recovery by remaining active. However, remaining active is one of the best things you can do for your back. In fact, prolonged bed rest is not recommended. Studies have shown that people with low back pain recover faster when they remain active. Movement helps to relieve muscle spasms and prevents loss of muscle strength.
Although high-impact activities should be avoided, it is fine to continue doing regular day-to-day activities and light exercises, such as walking. If certain activities cause the back to hurt too much, it is fine to stop that activity and try another.
If back pain is severe, bedrest may be necessary for a short period of time, generally no more than one day . When in bed, the most comfortable position may be to lie on the back with a pillow behind the knees and the head and shoulders elevated, or to lie on the side with the upper knee bent and a pillow between the knees.
Heat — Using a heating pad can help with low back pain during the first few weeks. It is not clear if cold packs help as well .
Work — Most experts recommend that people with low back pain continue to work if it is possible to avoid prolonged standing or sitting, heavy lifting, and twisting. Some people need to stay home from work if their occupation does not allow them to sit or stand comfortably. While standing at work, stepping on a block of wood with one foot (and periodically alternating the foot on the block) may be helpful.
Pain medications — Take a pain medication such as aspirin, acetaminophen (Tylenol®), or ibuprofen (eg, Advil®) or naproxen (Aleve®). Stronger pain medications, such as narcotics, are reserved for people whose pain is not relieved with acetaminophen or NSAIDs.
If medication is needed, it is usually more effective to take a dose on a regular basis for three to five days, rather than using the medication only when the pain becomes unbearable. (See “Patient information: Nonsteroidal antiinflammatory drugs (NSAIDs)”.)
Muscle relaxants (eg, cyclobenzaprine, Flexeril®) are available by prescription, but can cause drowsiness and are probably no better than ibuprofen in relieving pain . Muscle relaxants may be helpful before bedtime when used for a short time. People who need to be alert, such as while driving or operating machinery, should not use muscle relaxants.
Exercise — Back exercises or stretching routines should not be used immediately after a new episode of low back pain because this could worsen or prolong pain. However, as symptoms begin to resolve, a program of exercises can help to increase back flexibility and strengthen the muscles that support the back .
Recommended activities include those that involve strengthening and stretching, such as walking, swimming, use of a stationary bicycle, and low-impact aerobics. Avoid activities that involve twisting, bending, are high impact, or that make the back hurt more. Some specific exercises may help strengthen the muscles of the lower back. People with frequent episodes of low back pain should continue these exercises indefinitely to prevent new episodes.
Physical therapy — If back pain has been present for more than 4 to 6 weeks, a healthcare provider may recommend working with a physical therapist to develop a formal exercise program. Exercise programs may involve stretching, flexion and extension exercises, strengthening, aerobic activity, general overall fitness, or some combination of these components. The physical therapist may directly supervise exercise sessions, or can teach the person to perform the exercise program at home.
Manipulation — Manipulation is a technique used by physical therapists, chiropractors, osteopaths, massage therapists, and others to treat acute and chronic back pain. It involves moving a joint (spinal column) beyond the normal range of voluntary movement.
In clinical trials of people who had back pain for more than 4 weeks, manipulation was found to be safe and as effective as “conventional” treatments (eg, pain medication, rest, exercise) . The optimal number of manipulations is not known; most clinical trials used two treatments per week for two to three weeks.
Acupuncture — Acupuncture involves inserting very fine needles into specific points, as determined by traditional Chinese maps of the body’s flow of energy. Acupuncture may be a reasonable option for interested patients with access to an acupuncturist. In general, acupuncture is a safe treatment that may be helpful for chronic back pain . It is not clear if acupuncture is helpful for people with recent-onset (acute) low back pain.
Massage and yoga — A few studies have evaluated massage and yoga for back pain treatment. The benefit of massage or yoga was found to be greatest in people with chronic back pain who expected to improve with one of these treatments . (See “Fish oil and marine omega-3 fatty acids”, section on ‘Total mortality’.)
- Injections — Some clinicians recommend injections of a local anesthetic into the soft tissues of the back to relieve chronic pain, although it is not clear if these injections are effective. The areas targeted by these injections are called trigger points. Trigger point injections may be of benefit in people with chronic back pain.
Injections of a steroid medication are sometimes recommended for people with chronic low back pain with sciatica or radiculopathy. The injection is given into the epidural space, located below the spinal cord. Epidural steroid injections do appear to improve pain slightly at two and six weeks after the injection, but not at 3, 6, or 12 months after the injection. There is no evidence that epidural steroid injections are helpful for people with back pain without sciatica.
- Corsets and braces are not helpful in treating or preventing low back pain.
- Traction involves the use of weights to realign or pull the spinal column into alignment. Clinical studies have shown no benefit from traction in the treatment of back pain in the first few weeks.
- Mattress choice — The benefit of a firm mattress in preventing or treating low back pain has not been proven. In one study, medium firm mattresses were more likely to improve chronic back pain compared to firm mattresses .
- Other interventions include ultrasound, interferential therapy, short-wave diathermy transcutaneous electrical nerve stimulation, low-level laser therapy, all of which involve applying energy to the skin’s surface. None of these interventions have been proven to be effective, particularly during the first 4 to 6 weeks of an episode of back pain.
Chronic low back pain treatment — Long-term (chronic) back pain treatments are discussed in detail separately and are available by subscription. (See “Subacute and chronic low back pain: Nonsurgical interventional treatment” and “Subacute and chronic low back pain: Pharmacologic and noninterventional treatment”.)
LOW BACK PAIN SURGERY — Only a small minority of people with low back pain will require surgery. Surgery is necessary if there is evidence of cauda equina syndrome (problems with the nerves at the base of the spinal cord), another serious back condition like a tumor or infection, or severe weakness due to spinal stenosis or compression of a nerve root. (See “Subacute and chronic low back pain: Surgical treatment”.)
Surgery may also be considered for people with persistent radiculopathy due to herniated disc or spinal stenosis that has not responded to other (non-surgical) therapies. There is controversy about whether surgery is beneficial for people with degenerative disc disease alone.
Referral to an orthopedic surgeon or neurosurgeon is recommended under the following circumstances:
- Increasing neurologic problems (measurable weakness)
- Loss of sensation (eg, numbness) or bladder and bowel symptoms
- Failure to improve after four to six weeks of non-surgical management, with persistent and severe sciatica and evidence of nerve root involvement
PREVENTING LOW BACK PAIN — There are a number of ways to prevent low back pain from returning. Perhaps the most important are exercise and staying active. Regular exercise that improves cardiovascular fitness can be combined with specific exercises to strengthen the muscles of the hips and torso. The abdominal muscles are particularly important in supporting the lower back and preventing back pain. It is also important to avoid activities that involve repetitive bending or twisting and high-impact activities that increase stress in the spine.
Bend and lift correctly — People with low back pain should learn the right way to bend and lift. As an example, lifting should always be done with the knees bent and the abdominal muscles tightened to avoid straining the weaker muscles in the lower back (picture 1).
Take a break — People who sit or stand for long periods should change positions often and use a chair with appropriate support for the back. An office chair should be readjusted several times throughout the day to avoid sitting in the same position. Taking brief but frequent breaks to walk around will also prevent pain due to prolonged sitting or standing. People who stand in place for long periods can try placing a block of wood on the floor, stepping up and down every few minutes.