Don’t assume that an aching joint means that you have arthritis. If the pain came on suddenly, hurts more at night and gets better when you’re active, you might have bursitis.

Many of the body’s joints have one or more bursae (bur-SEE), fluid-filled sacs that rest between bones and tendons. Irritation of a bursa (the singular form) can cause intense pain that makes it difficult to move.

Bursitis usually occurs in the shoulder, hip, elbow or knee, but it also can occur in the heel and base of your big toe. Depending on the location and the degree of irritation, the pain can range from merely irritating to excruciating.

WHAT GOES WRONG

Bursae provide a lubricating surface between joint bones and the tendons and muscles that lie above. When you move, the tendons/muscles glide, with almost no friction, across the bursae.

Bursitis is caused when pressure and/or repetitive movements irritate a bursa and cause inflammation. Inflammation not only is painful, but it also increases the friction of moving tendons/muscles, which exacerbates the problem.

Bursitis can be triggered by trauma, such as a hard knock to the elbow or knee. However, most cases are due to repetitive movements (such as frequently lifting your arms over your head) or pressure (from kneeling or leaning on your elbows). People with hobbies or professions—electrician, carpet installer, musician, factory worker—that involve repetitive movements and/or pressure have the highest risk.

If the discomfort from the bursitis severely inhibits your range of motion and you quit moving normally, you can develop scar tissue that can lead to chronic inflammation and stiffness.

Example: One common disorder, adhesive capsulitis, often occurs in patients who first had shoulder bursitis and then put up with limited joint motion. This condition, also known as “frozen shoulder,” can cause severe pain and take many months to resolve.

Another risk: An infected bursa, known as septic bursitis.

BURSITIS OR SOMETHING ELSE?

Your doctor will press on different points around your painful joint to see if there’s tenderness above one or more bursae. It’s difficult to distinguish bursitis from tendonitis, inflammation of a tendon. Patients with bursitis often have tendonitis as well, because the increased friction from an inflamed bursa can irritate the tendon. Also, tendonitis can spread to the adjacent bursa. The distinction usually isn’t important because the treatments for each condition typically are the same.

Your doctor usually can distinguish bursitis from arthritis by your symptoms. In general, the pain caused by osteoarthritis (the most common form of arthritis) is more persistent…gets worse rather than better with continued movements…and usually is worse during the day, when patients are most active.

If your doctor isn’t sure what’s causing your pain, you probably will need an X-ray. It’s the only way to definitively distinguish arthritis from bursitis.

If your doctor suspects that a bursa might be infected, he/she will remove fluid with a needle and test it for infection. Bonus: Although the procedure is mildly uncomfortable, it usually will reduce bursitis pain almost immediately.

SELF-HELP FOR BURSITIS

Apply ice or a cold pack as soon as you feel pain. Chill the area for 10 to 15 minutes at a time, and repeat it once or twice an hour—or as often as you can—for at least 48 hours. Applying cold will help reduce swelling as well as pain. After 48 hours, intermittent heat is appropriate to increase circulation and promote healing.

You also can take an over-the-counter anti-inflammatory, such as ibuprofen (i.e., Advil, Motrin), following the directions on the label.

MEDICAL HELP

If you have severe pain, your doctor can inject the bursa with a mixture of cortisone and an anesthetic. The anesthetic will stop the pain instantly. The cortisone gradually will reduce swelling as well as pain. Most patients with bursitis who get an injection need only one treatment.

If you have septic bursitis, you’ll need antibiotics—the type will depend on the bacterium that’s causing the infection. Most patients will take antibiotics orally. Severe infections might need to be treated with intravenous antibiotic therapy.

When bursitis is severe and doesn’t improve after treatment, surgery may be needed to remove the bursa—but this is rarely necessary.

PREVENTION

To avoid bursitis…

Protect your joints as much as possible. For example, someone who spends a lot of time kneeling can wear knee pads. Or rest your weight on your forearms rather than on your elbows.

Take frequent breaks. If you’re laying tile, for example, stand up and walk around every 15 or 20 minutes.

Routinely move your joints through their full range of motion. Examples: Periodically move your arm in a complete circle—from front to back and from side to side. You can work the knee joint by lying on your back, with your knees bent, and slowly bringing the heel of your foot close to the buttocks.

Walking also is helpful, and using a bicycle is an excellent exercise for knees and hips. Doing shoulder exercises in a warm shower often is beneficial.

Source: James V. Luck, Jr., MD, an orthopedic surgeon, professor and residency program director of the UCLA/Orthopaedic Hospital Department of Orthopaedic Surgery. He is chairman of the national Medical Advisory Board for the Shriners Hospital for Children.