Quiz: What Do You Know About Low Back Pain?

Muscle spasms are the most common reason for low back pain. That's why some treatments include muscle relaxers. You can strain a muscle with an unexpected pull or twist. Your chances of muscle spasms go up if you have weak stomach muscles, tight hamstrings, any back weakness, or a pelvis that tilts forward more than normal.

Up to 80% of U.S. adults get low back pain at some point. Men and women are equally affected. Low back pain is more common as we get older, with people often having their first episode between ages 30 and 50. But it also can be the result of a sedentary lifestyle -- with too little (and occasionally too much) exercise.

And low back pain is the fifth most common reason for doctor visits.

Bed rest alone can actually make back pain worse. It can also lead to other conditions, like weakened muscles and blood clots in the legs. One study showed that people who continued their normal activities after a bout of low back pain had more flexibility than those who rested in bed for a week. Staying in the same position for too long can also make your joints stiff.

The lower back consists of five lumbar vertebrae. They are the weight-bearing part of the back and carry the most stress. The mid-back is made up of 12 thoracic vertebrae. The rib cage attaches here. This part of the back is very flexible to allow bending and twisting. The seven cervical vertebrae are in the neck.

Most of the time, you don't need an imaging test, particularly because most scans won't reveal a muscle spasm or ligament sprain. But your doctor may still order one for a few reasons, including if you injured your back or if the pain doesn't get better after several weeks.

Most back pain is caused by injury to the lower back or an ongoing health problem. Injuries include overuse of the back muscles, sports injuries, extreme lifting, or sudden jolts -- such as a car accident. Arthritis or a bulging disc are ongoing health conditions that may cause back pain.

Acute -- or short-term -- low back pain begins suddenly and may last several days or weeks. Chronic low back pain, which can be mild or severe, lasts longer than 3 months.

After the first flare-up, you might take a short rest period  -- 1-2 days -- applying ice for the first couple of days and then a heating pad to loosen tight muscles. Take an over-the-counter pain medication if you need it. You should try to stay as active as you can. If you do choose a day of bed rest, try to walk around every couple of hours. Movement can help speed up healing. You should see your doctor if the pain doesn't get better within 7-10 days or if it gets any worse.

Firmer may not always be better. People who sleep on a medium-firm mattress are more likely to report that their back pain got better while lying in bed or getting in or out of bed. So if you think you prefer a firm mattress, you might want to try medium-firm. This type may place less pressure on the shoulders and hips, allowing you to sleep in a more natural position on your side. Your mattress should be firm enough to keep your spine in the same position as good standing posture.

Things like chiropractic care, physical therapy, yoga, and massage may help. In fact, groups such as the American Pain Society and American College of Physicians recommend these treatments for people whose pain continues after more than a few weeks of self-care.

Let your doctor know if you have any of these symptoms or fever, weakness, trouble peeing, numbness in your legs, or weight loss without trying. Most short-term low back pain is treatable without surgery, but these other symptoms may point to a more serious problem.

Fewer than 2% of people with back pain will need an operation for a herniated or slipped disk -- a bulging disk that presses on the nerves next to it. Most people get better with simpler treatments -- heat and ice, rest, gentle exercise, and over-the-counter pain relievers.

Sciatica is leg pain caused by pressure on the sciatic nerve. The most common cause is a slipped disk. Other conditions, such as a narrowing of the spinal canal, also may cause it. The sciatic nerve extends from the spine to each leg. Pressure on it causes shock-like or burning pain in the lower back and buttocks and typically down one leg. The pain occasionally reaches the foot.

There are a few spinal conditions that involve twisting and spinal pain. Scoliosis -- or curvature of the spine -- is marked by a bending of the spine to the side. Kyphosis, which means "hunchback,"  is when the spine is bent forward. Lordosis, or “swayback,” means the spine has a backward curve.