Low backpain is very common and becomes more common as people age, affecting more than half of people over 60. It is one of the most common reasons for health care visits. Low backpain is very costly in terms of health care payments, disability payments, and missed work. However, the number of back injuries in the workplace is decreasing, perhaps because people are more aware of the problem and preventive measures have improved.
The spine (spinal column) consists of back bones (vertebrae). The vertebrae are covered by a thin layer of cartilage and separated and cushioned by shock-absorbing disks made of jelly-like material and cartilage. They are held in place by ligaments and muscles, which include the following:
- Two iliopsoas muscles, which run along both sides of the spine
- Two erector spinae muscles, which run along the length of the spine behind it
- Many short paraspinal muscles, which run between the vertebrae
Enclosed in the spine is the spinal cord . Along the length of the spinal cord, the spinal nerves emerge through spaces between the vertebrae to connect with nerves throughout the body. The part of the spinal nerve nearest the spinal cord is called the spinal nerve root. Because of their position, spinal nerve roots can be squeezed (compressed) when the spine is injured, resulting in pain.
The lower (lumbar) spine connects the chest to the pelvis and legs, providing mobility—for turning, twisting, and bending. It also provides strength—for standing, walking, and lifting. Thus, the lower backis involved in almost all activities of daily living. Low backpain can limit many activities and reduce the quality of life.
Types:Common types of backpain include local, radiating, and referred pain.
Local pain occurs in a specific area of the lower back. It is the most common type of backpain. The cause is usually a muscle sprain, a strain, or another injury. The pain may be constant and aching or, at times, intermittent and sharp. Sudden pain may be felt when the cause is an injury. Local pain can be aggravated or relieved by changes in position. The lower back may be sore when touched. Muscle spasms may occur.
Radiating pain is dull, aching pain that travels from the lower back down the leg. It may be accompanied by sharp, intense pain. It typically involves only the side or back of the leg rather than the entire leg. The pain may travel all the way to the foot or only to the knee. Radiating pain typically indicates compression of a nerve root caused by disorders such as a herniated disk, osteoarthritis, or spinal stenosis. Coughing, sneezing, straining, or bending over while keeping the legs straight may trigger the pain. If pressure on the nerve root is great or if the spinal cord is also compressed, the pain may be accompanied by muscle weakness in the leg, a pins-and-needles sensation, or even loss of sensation and loss of bladder or bowel control (incontinence).
Referred pain is felt in a different location from the actual cause of the pain. For example, some people who have a heart attack feel pain in their left arm. Referred pain in the lower back tends to be deep and aching, and its exact location is hard to pinpoint. Typically, movement does not worsen it, unlike pain from a musculoskeletal disorder.
CausesMost backpain is caused by disorders of the spine and the muscles, ligaments, and nerve roots around it or the disks between vertebrae. Often in such cases, no single specific cause can be identified. Whatever the cause, many factors such as fatigue, obesity, and lack of exercise can worsen backpain. Also, any painful disorder of the spine may cause reflex tightening (spasm) of muscles around the spine. This spasm worsens the existing pain. Stress may worsen low backpain, but how it does so is unclear.
Occasionally, backpain is due to disorders outside the spine, such as those of the kidneys and urinary tract, digestive tract, and blood vessels.
Common causes:The most common cause of low backpain is
- Muscle strains and ligament sprains
Other common causes of low backpain include
- Osteoarthritis
- Compression fractures
- A ruptured or herniated disk
- Lumbar spinal stenosis
- Spondylolisthesis
- Fibromyalgia
Compression (crush) fractures commonly develop when bone density decreases because of osteoporosis, which typically develops as people age. Vertebrae are particularly susceptible to the effects of osteoporosis. Compression fractures (which sometimes cause sudden, severe backpain) can be accompanied by compression of spinal nerve roots (which may cause chronic backpain). However, most fractures due to osteoporosis occur in the upper and middle back and cause upper and middle rather than low backpain.
A ruptured or herniated disk can cause low backpain. A disk has a tough covering and a soft, jelly-like interior. If a disk is suddenly squeezed by the vertebrae above and below it (as when lifting a heavy object), the covering may tear (rupture), causing pain. The interior of the disk can squeeze through the tear in the covering, so that part of the interior bulges out (herniates). This bulge can compress, irritate, and even damage the spinal nerve root next to it, causing more pain. A ruptured or herniated disk also commonly causes sciatica.
A Herniated DiskThe tough covering of a disk in the spine can tear (rupture), causing pain. The soft, jelly-like interior may then bulge out (herniate) through the covering, causing more pain. Pain occurs because the bulge puts pressure on the spinal nerve root next to it. Sometimes the nerve root becomes inflamed or is damaged.
More than 80% of herniated disks occur in the lower back. They are most common among people aged 30 to 50 years. Between these ages, the covering weakens. The jelly-like interior, which is under high pressure, may squeeze through a tear or a weakened spot in the covering and bulge out. After age 50, the interior of the disk begins to harden, making herniation less likely.
A disk may herniate because of a sudden, traumatic injury or repeated minor injuries. Being overweight or lifting heavy objects, particularly lifting incorrectly, increases the risk.
Often, herniated disks, even ones that appear obviously bulging or herniated on imaging tests such as magnetic resonance imaging (MRI) or computed tomography (CT), cause no symptoms. Herniated discs that do not cause symptoms are more common as people age. However, herniated disks may cause slight to debilitating pain. Movement often intensifies the pain.
Where the pain occurs depends on which disk is herniated and which spinal nerve root is affected. The pain may be felt along the pathway of the nerve compressed by the herniated disk. For example, a herniated disk commonly causes sciatica—pain along the sciatic nerve, down the back of the leg.
A herniated disk can also cause numbness and muscle weakness. If pressure on the nerve root is great, a leg may be paralyzed. Rarely, the disk can put pressure on the spinal cord itself, possibly causing weakness or paralysis of both legs. If the cauda equina (the bundle of nerves extending from the bottom of the cord) is affected, control of bladder and bowels can be lost. If these serious symptoms develop, medical attention is required immediately.
Most people recover without any treatment, usually within 3 months, but often much faster. Applying cold (such as ice packs) or heat (such as a heating pad) or using over-the-counter analgesics may help relieve the pain. Sometimes surgery to remove part or all the disk and part of a vertebra is necessary. In 10 to 20% of people who have surgery for sciatica due to a herniated disk, another disk ruptures.
What Is Sciatica?The two sciatic nerves are the widest and longest nerves in the body. Each is almost as wide as a finger. On each side of the body, the sciatic nerve runs from the lower spine, behind the hip joint, down the buttock and back of the knee. There the sciatic nerve divides into several branches and continues to the foot. When the sciatic nerve is pinched, inflamed, or damaged, pain—sciatica—may radiate along the length of the sciatic nerve to the foot. Sciatica occurs in about 5% of people who have backpain.
In some people, no cause can be detected. In others, the cause may be a herniated disk, irregular projections of bone due to osteoarthritis, spinal stenosis, or swelling due to a sprained ligament. Rarely, Paget disease of bone, nerve damage due to diabetes (diabetic neuropathy), a tumor, or an accumulation of blood (hematoma) or pus (abscess) causes sciatica. Some people seem to be prone to sciatica.
Sciatica usually affects only one side. It may cause a pins-and-needles sensation, a nagging ache, or shooting pain. Numbness may be felt in the leg or foot. Walking, running, climbing stairs, straightening the leg, and sometimes coughing or straining worsens the pain, which is relieved by straightening the back or standing.
Often, the pain goes away on its own. Resting, sleeping on a firm mattress, taking over-the-counter acetaminophen
or nonsteroidal anti-inflammatory drugs (NSAIDs), and applying heat and cold may be sufficient treatment. For many people, sleeping on their side with the knees bent and a pillow between the knees provides relief. Stretching the hamstring muscles gently after warming up may help.
Occasionally, other treatments are used, depending on the cause of sciatica. Treatments may include physical therapy, corticosteroids injected into the back, anticonvulsants, tricyclic depressants, and, for severe and persistent pain, surgery.
Lumbar spinal stenosis is narrowing of the spinal canal (which runs through the center of the spine and contains the spinal cord) in the lower back. It is a common cause of low backpain in older people. Spinal stenosis also develops in middle-aged people who were born with a narrow spinal canal. It is caused by such disorders as osteoarthritis, spondylolisthesis, rheumatoid arthritis, ankylosing spondylitis, and Paget disease of bone. Spinal stenosis may cause sciatica as well as low backpain.
Spondylolisthesis is partial displacement of a vertebra in the lower back. It usually occurs in people who have a common bone birth defect (spondylolysis) that weakens part of the vertebrae. Usually, during adolescence or young adulthood (often in athletes), a minor injury causes a part of the vertebra to fracture. The vertebra then slips forward over the one below it. If it slips far, pain can result. Spondylolisthesis can also occur in older adults. People with spondylolisthesis are at risk of developing lumbar spinal stenosis.
Fibromyalgia is a common cause of body pain, sometimes including lowbackpain. This disorder causes chronic widespread (diffuse) pain in muscles and other soft tissues in areas outside the lower back.
Did You Know...
- Strengthening abdominal muscles, as well asback muscles, helps prevent low backpain.
- Spinal infections
- Spinal tumors
- A bulge (aneurysm) in the large artery in the abdomen (abdominal aortic aneurysm)
- Certain digestive disorders, such as a perforated peptic ulcer, diverticulitis, and pancreatitis
- Certain urinary tract disorders, such as kidney infections, kidney stones, and prostate infections
- Certain disorders involving the pelvis, such as ectopic pregnancy, pelvic inflammatory disease, and cancer of the ovaries or other reproductive organs
EvaluationThe doctor aims to identify any serious disorders. Because low backpain is often caused by several problems, diagnosing a single cause may not be possible. Doctors may only be able to tell that the cause is a musculoskeletal disorder and is not serious.
Warning signs:In people with low backpain, certain symptoms and characteristics are cause for concern. They include
- A history of cancer
- Pain for more than 6 weeks
- Numbness, weakness in one or both legs, difficulty emptying the bladder (retention of urine), or loss of bladder or bowel control (incontinence)—symptoms that suggest nerve damage
- Fever
- Weight loss
- Severe pain at night
- Pain in people aged 55 or older without an obvious explanation (such as an injury)
- Use of drugs that suppress the immune system, HIV infection or AIDS, use of injected drugs, recent surgery, or a wound—conditions that increase the risk of infection
- Difficulty breathing, paleness, light-headedness, sudden sweating, a racing heartbeat, or loss of consciousness—symptoms that suggest an abdominal aortic aneurysm
- Vomiting, severe abdominal pain, or stool that is black or bloody—symptoms that suggest a digestive disorder
- Difficulty urinating, blood in the urine, or severe crampy pain on one side radiating into the groin—symptoms that suggest a urinary tract disorder
What the doctor does:Doctors first ask questions about the person's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination often suggests a cause and the tests that may need to be done.
Doctors ask questions about the pain:
- What is the pain like?
- How severe is it?
- Where is it and where does it radiate?
- What relieves or worsens it (for example, changes in position or weight bearing)?
- When and how did it start?
- Are there other symptoms (such as numbness, weakness, retention of urine, or incontinence)?
- Pain in an area that is tender to the touch and is worsened by changes in position or weight bearing is usually local pain.
- Pain on only one side of the back probably does not involve the spine.
- Pain that radiates down the leg, such as sciatica, is usually caused by compression of a spinal nerve root.
- Pain that is moderate or severe, is not affected by changes in position of the back, and is not accompanied by tenderness may be referred pain.
- Pain that is constant, severe, progressively worse, and unrelieved by rest, particularly if it keeps the person awake at night, may indicate cancer or an infection.
Doctors may ask the person to move in certain ways to determine the type of pain. For example, they may ask the person to lie flat, then lift the leg without bending the knee, and then stand and bend over. Doctors may also check a person's abdomen for tenderness or a mass, particularly in people over 55, who may have an aortic aneurysm. They examine the prostate in men by doing a digital rectal examination and the internal reproductive organs in women by doing a pelvic examination.
With information about the pain, the person's medical history, and results of a physical examination, doctors may be able to determine as much as is necessary about the cause.
- often occurs on one or both sides of the spine
- Worsens with movement and lessens with rest
- Typically develops while lifting, bending, or twisting
Osteoarthritis, sometimes with compression of a spinal nerve root
Pain in the middle of the back that sometimes
- Travels down a leg
- Is accompanied by numbness and/or weakness
- Is worsened by coughing, sneezing, or straining
X-rays
Compression fractures
Pain in the middle of the back, sometimes starting suddenly
Usually in people who are older or who have osteoporosis
X-rays
A herniated disk, usually with compression of a spinal nerve root
Pain in the middle of the back that usually
- Travels down a leg
- Is accompanied by numbness and/or weakness
- Is worsened by coughing, sneezing, straining, or leaning forward
Sometimes MRI or CT
Lumbar spinal stenosis
Pain in the middle of the back that
- Is worsened by straightening the back(as when walking or leaning back)
- Is relieved by leaning forward
- May travel down one leg or both legs
A doctor's examination
Sometimes MRI
Spondylolisthesis, sometimes with compression of a spinal nerve root
Pain in the middle of the back that sometimes
- Travels down a leg
- Is accompanied by numbness and/or weakness
- Is worsened by coughing, sneezing, or straining
X-rays
Fibromyalgia
Aching and stiffness in many areas of the body (not just the lower back)
Sore areas that are tender to the touch
Often poor sleep
Most common among women aged 20 to 50
A doctor's examination
Less common causes
Ankylosing spondylitis (inflammation of the spine and large joints)
Stiffness, often worse immediately after awakening
Progressive loss of back flexibility, often causing the back to hunch forward
Sometimes a painful red eye and/orpain in other joints
Often in young men
X-rays
Blood tests
Compression of the spinal cord
Pain in the middle of the back
Numbness and weakness of usually both legs
MRI
Cauda equina syndrome
Numbness in the groin and around the anus
Loss of bladder and/or bowel control (incontinence)
MRI
Shingles
Pain in a strip of skin on either the right or left side, but not both
Usually blisters that develop on the painful strip of skin a few days after the pain starts
A doctor's examination
Cancer
Progressively worsening pain, regardless of position or activity
Sometimes loss of appetite and/or weight
Usually x-rays
MRI or CT
Infection
- In the vertebrae (osteomyelitis)
- In the disk (diskitis)
- Around the spinal cord (spinal epidural abscess)
Sometimes fever and/or night sweats
Often in people who have had backsurgery, who have an immune disorder, who take drugs that suppress the immune system, or who use IV drugs
Usually x-rays
MRI or CT
Blood tests
*Features include symptoms and results of the doctor's examination. Features mentioned are typical but not always present.
†If pain resolves without treatment and no warning signs are present, testing may not be necessary.
CT = computed tomography; IV = intravenous; MRI = magnetic resonance imaging.
Testing:Usually, no tests are needed because most backpain results from strains and sprains or other minor musculoskeletal disorders and resolves within 6 weeks. Imaging tests are often needed if
- Another cause is suspected.
- Warning signs are present.
- Backpain persists.
If compression of the spinal cord is suspected, MRI is done immediately. Rarely, when results of MRI are unclear, myelography with CT is required. Rarely, if cancer or infection is suspected, removal of tissue (biopsy) is necessary. Occasionally, electromyography and nerve conduction studies are done to confirm the presence, location, and sometimes duration and severity of nerve root compression.
PreventionThe most effective way to prevent low backpain is to exercise regularly. Aerobic exercise and specific muscle-strengthening and stretching exercises can help.
Aerobic exercise, such as swimming and walking, improves general fitness and generally strengthens muscles.
Specific exercises to strengthen and stretch the muscles in the abdomen, buttocks, and back (core muscles) can help stabilize the spine and decrease strain on the disks that cushion the spine and the ligaments that hold it in place.
Muscle-strengthening exercises include pelvic tilts and abdominal curls. Stretching exercises include the sitting leg stretch and knee-to-chest stretch. Stretching exercises can increase backpain in some people and therefore should be done carefully. As a general rule, any exercise that causes or increases backpain should be stopped. Exercises should be repeated until the muscles feel mildly but not completely fatigued. Breathing during each exercise is important. People who have backpainshould consult a doctor before beginning to exercise.
Exercises to Prevent Low Back PainPelvic Tilts
Lie on the back with the knees bent, the heels on the floor, and the weight on the heels. Press the small of the back against the floor, contract the buttocks (raising them about half an inch from the floor), and contract the abdominal muscles. Hold this position for a count of 10. Repeat 20 times.
Abdominal Curls
Lie on the back with the knees bent and feet on the floor. Place the hands across the chest. Contract the abdominal muscles, slowly raising the shoulders about 10 inches from the floor while keeping the head back (the chin should not touch the chest). Then release the abdominal muscles, slowly lowering the shoulders. Do 3 sets of 10.
Knee-to-Chest Stretch
Lie flat on the back. Place both hands behind one knee and bring it to the chest. Hold for a count of 10. Slowly lower that leg and repeat with the other leg. Do this exercise 10 times.
Sitting Leg Stretch
Sit on the floor with the knees straight but slightly flexed (not locked) and the legs as far apart as possible. Place both hands on the same knee. Slowly slide both hands toward the ankle. Stop if pain is felt, and go no farther than a position that can be held comfortably for 10 seconds. Slowly return to a sitting position. Repeat with the other leg. Do this exercise 10 times for each leg.
Exercise can also help people maintain a desirable weight. Weight-bearing exercise can help people maintain bone density. Thus, exercise may reduce the risk of developing two conditions that can lead to low backpain—obesity and osteoporosis.
Maintaining good posture when standing and sitting reduces stress on the back. Slouching should be avoided. Chair seats can be adjusted to a height that allows the feet to be flat on the floor, with the knees bent up slightly and the lower back flat against the back of the chair. If a chair does not support the lower back, a pillow can be used behind the lower back. Sitting with the feet on the floor rather than with the legs crossed is advised. People should avoid standing or sitting for long periods. If prolonged standing or sitting is unavoidable, changing positions frequently may reduce stress on the back.
Sleeping in a comfortable position on a firm mattress is recommended. People who sleep on their backcan place a pillow under their knees. People who sleep on their side should use a pillow to support their head in a neutral position (not tilted down toward the bed or up toward the ceiling). They should place another pillow between their knees with their hips and knees bent slightly.
Learning to lift correctly helps prevent back injury. The hips should be aligned with the shoulders (that is, not rotated to one side or the other). People should not bend over with their legs nearly straight and reach out with their arms to pick up an object. Instead, they should bend at the hips and knees. Bending this way keeps the back straighter and brings the arms down to the object with the elbows at the side. Then, keeping the object close to the body, they lift the object by straightening their legs. This way, the legs, not the back, lift the object. Lifting an object over the head or twisting while lifting increases the risk of back injury.
Stopping smoking is also recommended.
TreatmentIf a specific cause can be diagnosed, that disorder is treated. For example, antibiotics are used to treat a prostate infection. However, there is no specific treatment for musculoskeletal pain due to sprains or strains nor for many other musculoskeletal causes. But many general measures can help. Usually, these general measures are also used when a spinal nerve root is compressed.
General measures:Measures include
- Modifying activities
- Taking drugs that relieve pain
- Applying heat or cold to the painful area
- Doing exercises
Acetaminophen
is usually recommended for pain relief unless inflammation is present. If inflammation is present, over-the-counter or prescription nonsteroidal anti-inflammatory drugs can relieve pain and reduce inflammation. Ifacetaminophen
or NSAIDs do not provide sufficient pain relief, opioid analgesics may be required.
Muscle relaxants, such as carisoprodol
, cyclobenzaprine
, diazepam
, metaxalone
, ormethocarbamol
, are sometimes given to relieve muscle spasms, but their usefulness is controversial. These drugs are not recommended for older people, who are more likely to have side effects.
Application of heat or cold may help. Cold is usually preferred to heat during the first 2 days after an injury. Ice and cold packs should not be applied directly to the skin. They should be enclosed (for example, in plastic) and placed over a towel or cloth. The ice is removed after 20 minutes, then reapplied for 20 minutes over a period of 60 to 90 minutes. This process can be repeated several times during the first 24 hours. Heat, using a heating pad, can be applied for the same periods of time. Because the skin on the back may be insensitive to heat, heating pads must be used cautiously to prevent burns. People should not use a heating pad at bedtime to avoid the risk of falling asleep with the pad still on their back.
Massage may speed the resolution of musculoskeletal pain due to muscle spasm, strains, or sprains. Some studies suggest that acupuncture may have similar benefits, but others suggest little or no benefit. Spinal manipulation, done by chiropractors or some other doctors (such as osteopathic doctors), may also speed the resolution of pain due to muscle spasm, strains, or sprains. However, it may have risks for people with osteoporosis or a herniated disk.
After the pain has subsided, light activity, as recommended by a doctor or physical therapist, can speed healing and recovery. Specific exercises to strengthen and stretch the back and to strengthen core muscles are usually recommended to help prevent low backpain from becoming chronic or recurring.
Other preventive measures (maintaining good posture, using a firm mattress with appropriately placed pillows, lifting correctly, and stopping smoking) should be continued or started. In response to these measures, most episodes of backpain resolve in several days to 2 weeks. Regardless of treatment, 80 to 90% of such episodes resolve within 6 weeks.
Treatment of chronic pain:Additional measures are needed for chronic low backpain. Aerobic exercise may help, and weight reduction, if necessary, is advised. If analgesics are ineffective, other treatments can be considered.
Transcutaneous electrical nerve stimulation (TENS) may be used. The TENS device produces a gentle tingling sensation by generating a low oscillating current. This current can block transmission of some pain sensation from the spinal cord to the brain. The current can be applied to the painful area several times a day for 20 minutes to several hours at a time, depending on the severity of the pain.
Sometimes a corticosteroid (such as dexamethasone or methylprednisolone
) plus a local anesthetic (such as lidocaine
) can be periodically injected into the epidural space—between the spine and the outer layer of tissue covering the spinal cord. These injections are more effective for sciatica caused by a herniated disk than for lumbar spinal stenosis. However, they are usually effective only for several days to weeks. Their main use is to relieve pain enough that an exercise program, which can provide long-term pain relief, can be started.
Surgery for back pain:If a herniated disk is causing relentless or chronic sciatica, weakness, loss of sensation, or loss of bladder and bowel control, surgical removal of the disk (diskectomy) and sometimes part of the vertebra (laminectomy) may be necessary. A general anesthetic is usually required. The hospital stay is usually 1 or 2 days. Often, microsurgical techniques, with a small incision and regional spinal anesthesia (which numbs only a specific part of the body), can be used to remove the herniated portion of the disk. Hospitalization is not required. However, when the incision is small, the surgeon may not be able to see and therefore may not remove all fragments of the herniated disk. After either procedure, most people can resume all of their activities in a few weeks. More than 90% of people recover fully.
For severe spinal stenosis, a large part of a vertebra may be surgically removed to widen the spinal canal. A general anesthetic is usually required. The hospital stay is usually 4 or 5 days. People may need 3 to 4 months before they can resume all of their activities. About two thirds of people have a good or full recovery. For most of the rest, such surgery prevents symptoms from worsening.
When the spine is unstable (as may result from severe osteoarthritis), surgery can be done to fuse vertebrae together. However, fusion decreases mobility and may put additional stress on the rest of the spine.