Lower Back Pain Causes, Risk Factors, Health Tips
- Facts about back pain
- Understanding lower back pain
- Causes of lower back pain
- Risk factors
- Health tips
- In the United States, approximately 90% of adults experience back pain at some time in their life.
- Approximately 50% of all patients who suffer from an episode of low back pain will have a recurrent episode within one year.
- Majority of acute and chronic back pain are benign. In more than 95% of cases, the underlying cause is not serious.
- Only 10% of those suffering from acute back pain require special diagnostic testing.
The back consists of a complex arrangement of bone, ligaments, joints, muscles, and nerves. Back pain can result from a problem with any of these components. Back pain is the second most common neurological ailment in the United States. Only headache is more common. The most common type of back pain is low back pain. That's because the lower portion of the back is under the most pressure when a person is sitting or lifting, and it can be easily damaged.
Nearly everyone at some point has back pain. Fortunately, most occurrences of lower back pain go away within a few days. Others take much longer to resolve or lead to more serious conditions.
Lower back pain is often described as sudden, sharp, persistent, or dull pain felt below the waist. It can be either acute or chronic condition.
Acute or short-term lower back pain has a sudden onset and generally lasts from a few days to a few weeks. Most acute back pain is mechanical in nature - the result of trauma to the lower back or a disorder such as arthritis. The structures damaged will more than likely be soft tissue like muscles, ligaments and tendons. Acute low back pain is usually not a serious condition - even if the pain is bad. Most cases of acute lower back pain improve within a few days, or sometimes within a few weeks.
Chronic lower back pain is pain that persists for more than 3 months. Chronic lower back pain usually has a more insidious onset, occurring over a long period of time. It is often progressive and the cause can be difficult to determine. Physical causes may include osteoarthritis, rheumatoid arthritis, degeneration of the discs between the vertebrae or a lumbar disc herniation.
There is usually no single identifiable cause for an episode of back pain, because of the complex composition of the human spine. Most back pain comes from the soft tissues of the spine: ligaments, muscles and joints. A substantial proportion of patients who develop chronic lower back pain have no identifiable structural pathology capable of explaining the pain. Pain specialists sometimes attribute the pain in these patients to unknown musculoskeletal factors. Sometimes the cause of lower back pain is entirely unknown.
The following parts of spinal anatomy can cause pain:
- large nerve roots in the low back that go to the legs and arms
- smaller nerves that innervate the spine in the low back
- large paired lower back muscles (erector spinae)
- bones, ligaments and joints
- intervertebral disc
Diseases and health conditions that can cause lower back pain include:
- Muscle or ligament strain. Lower back muscles work hard even with simple activities such as sitting, standing and walking. Because of the heavy demands put on them, these muscles are one of the most common sources of low back pain. Heavy lifting or abrupt stretching or twisting can tear or strain the lower back muscles and ligaments, and the resulting muscle spasms (contractions) can be severely painful.
- Herniated spinal disk (slipped disc). Herniated disks are a common cause of chronic lower back pain. Disk herniation is a disorder in which a spinal disk begins to bulge out from its position between two vertebrae. Herniated disc has the potential to cause compression against a nerve, producing radicular pain. This pain is caused by compression of the nerves as they exit the spinal column. The pain may be felt radiating into the buttock or down the leg, and may be accompanied by a sensation of numbness or tingling in the leg. Studies have shown that most herniated discs occur in the lower, lumbar portion of the spinal column.
- Spinal stenosis (narrowing of the spinal canal). Spinal stenosis is a disease that is caused by a gradual narrowing of the spinal canal. It results mostly from degenerative changes (osteoarthritis) in the spine, particularly from bony formations called osteophytes, which form around the joints of the spine. If the spinal canal becomes too tight, back pain can be the result. Spinal stenosis affects the aging population. The condition may cause back pain and pain in the thigh or leg, that often is made worse with long periods of standing or walking. Some studies suggest that spinal stenosis accounts for approximately 3% of low back pain.
- Degenerative disc disease. Chronic back pain may be caused by degenerative disk disease, which refers to a thinning and drying out of the disks over time that can lead to altered spine mechanics and perhaps to nerve irritation. Disk disease accounts for about 10% of lower back pain.
- Sciatica. Sciatica is a condition in which a herniated or ruptured disc presses on the sciatic nerve, the large nerve that extends down the spinal column to its exit point in the pelvis and carries nerve fibers to the leg. This compression causes shock-like or burning pain along the large sciatic nerve, from the lower back down through the buttocks and along the back of the leg.
- Osteoarthritis (degenerative joint disease). The joints that allow mobility and stability are subject to wear and tear. Facet joints allow movement of the spine. As facet joints degenerate, they may not align correctly, and the cartilage and fluid that lubricates the joints may deteriorate. Bone then rubs against bone, which can be very painful.
- Osteoporosis. Osteoporosis is a metabolic bone disease marked
by progressive decrease in bone density and strength. Fracture of brittle,
porous bones in the spine and hips results when the body fails to produce
new bone or absorbs too much existing bone. Women are four times more
likely than men to develop osteoporosis. Osteoporosis can cause a number
of orthopedic problems and generalized discomfort. Back pain from osteoporosis
is most commonly related to compression fractures of the vertebra.
- Arthritis. Arthritis most commonly affects joints such as the
knees and fingers. However, arthritis can affect any joint in the body,
including the small joints of the spine. Arthritis of the spine can cause
back pain with movement.
- Skeletal irregularities (deformities). Skeletal irregularities
produce strain on the vertebrae and supporting muscles, tendons, ligaments,
and tissues supported by spinal column. These irregularities include:
- scoliosis, a curving of the spine to the side
- kyphosis, in which the normal curve of the upper back is severely rounded
- lordosis, an abnormally accentuated arch in the lower back
- back extension, a bending backward of the spine
- back flexion, in which the spine bends forward.
- Fibromyalgia. Fibromyalgia is a chronic disorder characterized by widespread musculoskeletal pain, fatigue, and multiple tender points, particularly in the neck, spine, shoulders, and hips. Lower back pain resulting from fibromyalgia is real, but can also be subjective. Many people with this condition find that emotional stress makes the pain worse. Fibromyalgia may cause chronic back pain.
- Spondylolysis. Spondylolysis is a defect that occurs in the posterior part of the spine known as the pars intra-articularis. This disorder is essentially a stress fracture of part of the spine. The spinal cord or nerves leaving the cord can be compressed, causing pain in the back or legs.
- Spondylolisthesis. Spondylolisthesis is a relatively common condition, especially among older people. Spondylolisthesis occurs when one vertebra slips forward on the adjacent vertebrae. This will produce both a gradual deformity of the lower spine but also a narrowing of the vertebral canal. The most common cause of spondylolisthesis is due to degenerative changes causing loss of the normal stabilizing structures of the spinal column. If the spine becomes unstable enough, back pain can become a problem.
- Spondylitis. Spondylitis refers to chronic back pain and stiffness caused by a severe infection to or inflammation of the spinal joints. There are also other painful inflammations in the lower back, including osteomyelitis (infection in the bones of the spine) and sacroiliitis (inflammation in the sacroiliac joints).
- Vertebral body fractures. Fractures, which are usually quite painful, can occur for a variety of reasons. First, and most obviously, trauma. Fractures of the vertebrae may be caused by significant force, such as from an auto or bicycle accident, a direct blow to the spine, or compressing the spine by falling onto the buttocks or head. Osteoporosis, which is weakening of the bones due to loss of calcium, can predispose the bones to fracture. In a person with osteoporosis, even a small amount of force put on the spine, as from a sneeze, may cause a compression fracture.
- Pinched nerve. Pinched nerve (or radiculopathy) occurs when something rubs or presses against a nerve, creating irritation or inflammation. Radiculopathy can result from a herniated disc, bone spur, and vertebral fracture, and many other conditions.
- Ankylosing spondylitis. Ankylosing spondylitis is a type of arthritis that primarily affects the spine. It is believed to be a hereditary disease in most cases. Ankylosing spondylitis causes inflammation of the ligaments and tendons that connect the vertebrae and ultimately results in fusion of the spine.
- Atherosclerosis. Atherosclerosis (hardening of the arteries) involving the large blood vessels that run just in front of the spine (such as the aorta) may be a cause of back pain in some patients. For example, an abdominal aortic anuerysm, a complication of advanced atherosclerosis, may cause fluctuating back pain, at least for a period of time. How often atherosclerosis is involved in the development of chronic pain is not known.
- Diseases of the viscera. Diseases of other organs, such as uterine or pelvic infections in women, kidney infections, and gastrointestinal disease such as pancreatitis and cholecystitis, can also cause pain that can be referred to the low back.
Many factors increase the risk of developing low back pain. Some of these factors are important risk factors for the development of persistent back pain:
- Aging process. Aging produces wear and tear on the spine that
may result in conditions that produce back pain. Intervertebral discs
begin deteriorating and growing thinner by age 30. One-third of adults
over 20 show evidence of herniated discs (although only 3% of these discs
cause symptoms). As people continue to age and the discs lose moisture
and shrink, the risk for spinal stenosis increases. The incidence of low
back pain and sciatica increase in women at the time of menopause as they
lose bone density. In the older adults, osteoporosis and osteoarthritis
are also common.
- Genetic factors. Many people have a genetic susceptibility to low back pain, usually from inheriting spinal structural abnormalities.
- Physically demanding occupations, heavy physical work. Physically demanding occupations that require repetitive bending and lifting have a high incidence of back injury (e.g., construction worker, caregiver). Jobs that require long hours of standing without a break (e.g., hairdresser) or sitting in a chair (e.g., keyboard operator) that does not support the back well put a person at risk for neck and lower back injury.
- Sedentary lifestyle. People who do not exercise regularly face an increased risk for lower back pain, especially during times when they suddenly embark on stressful unaccustomed activity, such as shoveling, digging, or moving heavy items. Although no definitive studies have been done to prove the relationship between lack of exercise and low back pain, sedentary living is probably a primary nonmedical culprit contributing to this condition.
- Smoking. Smokers are at higher risk for back problems, perhaps because smoking decreases blood circulation, but the association may also be due to an unhealthy lifestyle in general.
- Poor Posture and Alignment. Poor posture or improper alignment may predispose individuals to developing back pain over time as this can cause undue stress on certain areas of the back. Poor posture, such as slouching in a chair, driving hunched over, standing incorrectly, and using poor body mechanics when lifting and carrying heavy loads are risk factors. Sleeping on a soft or sagging mattress also can lead to back pain.
- Obesity. Several studies have shown an increase in back pain in obese patients, especially in women. Back has a natural curve of the lower spine. However, abdominal fat can pull this part of the spine forward and downward. During pregnancy, the change in weight and where that weight is located puts a new strain on the back.
- Always stretch before exercise or other strenuous physical activity.
- Don’t slouch when standing or sitting. When standing, keep your weight balanced on your feet. Your back supports weight most easily when curvature is reduced.
- At home or work, make sure your work surface is at a comfortable height for you.
- Sit in a chair with good lumbar support and proper position and height for the task. Keep your shoulders back. Switch sitting positions often and periodically walk around the office or gently stretch muscles to relieve tension. A pillow or rolled-up towel placed behind the small of your back can provide some lumbar support. If you must sit for a long period of time, rest your feet on a low stool or a stack of books.
- Wear comfortable, low-heeled shoes.
- Sleep on your side to reduce any curve in your spine. Always sleep on a firm surface.
- Ask for help when transferring an ill or injured family member from a reclining to a sitting position or when moving the patient from a chair to a bed.
- Don’t try to lift objects too heavy for you. Lift with your knees, pull in your stomach muscles, and keep your head down and in line with your straight back. Keep the object close to your body. Do not twist when lifting.
- Maintain proper nutrition and diet to reduce and prevent excessive weight, especially weight around the waistline that taxes lower back muscles. A diet with sufficient daily intake of calcium, phosphorus, and vitamin D helps to promote new bone growth.
- If you smoke, quit. Smoking reduces blood flow to the lower spine and causes the spinal discs to degenerate.
- Don't push with your arms when you move a heavy object. Turn around and push backwards so the strain is taken by your legs.
- When lifting a heavy object keep the object close to your body and bend your knees. The stronger your legs are, the easier it will be to lift.
- Avoid lifting heavy objects higher than your waist.
- Sit close to the pedals when you drive and use your seat belt and a hard backrest or pillow.
- Push rather than pull when you must move heavy objects.
- Exercise regularly. An inactive lifestyle contributes to lower back pain.
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