Knowing Your Risk Factors
Because the specific cause of most back pain is mysterious, health-care providers often can’t say why one person gets it and another doesn’t. You should talk with your health-care provider to learn if you have any risk factors — that is, conditions that give you a greater chance of developing low back pain. For example, some conditions, such as pregnancy, are known to increase the risk of back pain.
And getting older is a risk factor because certain diseases common in old age can cause back pain; examples include degenerative disk disease, degenerative arthritis and fractures related to osteoporosis. Similarly, having a family history of these diseases can put you at risk. People in certain occupations that stress the back are also at higher risk — especially those whose jobs require long periods of sitting, repeated heavy lifting or pulling, or frequent bending or twisting of the back.
Of course, many people with risk factors never develop low back pain, and many with pain have no obvious risk factors.
Enumerating The Causes Of Low Back Pain
Any part of the lower back’s complex system — vertebrae, disks, nerves, muscles — can become a source of pain, as can nearby organs. The following are some common (and not-so-common) causes of low back pain.
- Muscle or ligament strain. Some of the largest, hardest-working muscles in the body are in or near the lower back. And unlike muscles stressed primarily during exercise, the 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.
- Degenerative joint disease. Like all of the body’s joints, those in the lower back connecting the spinal column and pelvis are subject to wear and tear. The shiny, smooth cartilage that lines the joints wears away, leaving bone to rub on bone. This degenerative process, common in old age or after injury, is also known as osteoarthritis.
- Disk disease. As you age, the gelatinous filling in the disks in your spine begins to dry and harden, and the disks can bulge or rupture. A bulging disk is often seen on magnetic resonance imaging (MRI) but usually does not cause symptoms.
- A ruptured disk is commonly called a slipped disk, or herniated disk. Material from a ruptured disk can press on the spinal cord or nerves that pass through tight spaces between the vertebrae. Even a little pressure or pinching can cause low back pain, as well as leg weakness, numbness or tingling. When the nerves that lead to the sciatic nerve are compressed, sciatica may develop.
- Spinal stenosis. Narrowing (stenosis) of the spinal canal — the space surrounding the spinal cord that serves to protect it — may be caused by calcium deposits in ligaments, degenerative joint disease or disk disease, or it may be present since birth. Any of these problems alone or in combination can put pressure on the spinal cord or a nearby nerve, causing low back pain.
- Spondylolisthesis and spondylolysis. Spondylolisthesis is a relatively common condition, especially among older people, in which one vertebra slides forward on another. When a tiny defect or fracture in the bones at the back of a vertebra is also present, the condition is called spondylolysis. In either case, the spinal cord or nerves leaving the cord can be compressed, causing pain in the back or legs.
- Osteoporosis with compression fracture. In osteoporosis — a progressive disease that commonly affects postmenopausal women — the bones become weaker and more porous. Although osteoporosis is painless, it increases the risk of fracture of the hip, wrist and vertebrae. Vertebral fractures themselves may be painful, as can be the resulting abnormal curvature of the spine or pressure on nerves.
- Inflammatory arthritis of the lower back. Although relatively rare, sacroiliitis (inflammation of the sacroiliac joint, which connects the spine and pelvis) or spondylitis (inflammation of the joints between the vertebrae) may cause low back pain, especially in young adults.
- Cancer. Cancer is a rare cause of low back pain. It can start in the structures of the lower back, including bones or the spinal cord. However, when cancer does occur in the lower back, it usually has spread from elsewhere in the body, such as the breast, prostate, lung or kidney.
- Infection. In rare cases, bacterial infections of the bones or disks can cause low back pain. When this does happen, the infection usually has spread from the bloodstream or from contamination introduced by an injury or during surgery.
- Organ-related pain. The kidneys are located in the midback and are connected to the bladder by a tube called the ureter. Kidney stones lodged in the ureter or infection or blockage anywhere along the way can cause severe low back pain or flank pain. Fibroids in the uterus and disorders of the ovaries can lead to low back discomfort, as can diverticulitis, an inflammation of the intestines. Back pain during pregnancy is common, probably because the enlarging uterus stretches nearby ligaments and shifts the center of gravity, straining back muscles. Finally, the aorta, the body’s largest artery, travels out of the heart and down to the abdomen and pelvis; an aneurysm (ballooning out of the aortic artery) can cause low back pain. Rupture of the aorta can cause back pain, too, although this is an emergency situation that demands an urgent trip to the hospital.