The Facts

Bursitis is an inflammation of a bursa, which is a fluid-filled sac located near the bones around the joints and between muscle attachments at a joint. Their purpose is to cushion and lubricate the movement of tendons and muscle over bone.

The joint most commonly affected with bursitis is the shoulder. Other joints that may develop bursitis include the elbow, the knee (this is also known as housemaid's knee), and the base of the big toe (called a bunion). Bursitis may be acute or chronic. The chronic form tends to come and go over cycles of weeks or months.

Causes

Bursitis can start in four different ways:

Trauma or injury: Ordinarily, a muscle-pull shouldn't affect a bursa. An injury that causes deep bruising, however, could provoke a brief inflammation of a bursa. This will often clear up without treatment.

Overuse: Many forms of bursitis have nicknames like "housemaid's knee," "miner's elbow," and even "tailor's bottom." Inflammation can result from repetitive strain placed on a joint, or continual pressure on the bursa itself (for example, by kneeling).

Inflammatory arthritic disease: Conditions like rheumatoid arthritis and gout can lead to the release of inflammatory agents into the bursae. Also, calcium-based crystals can form in the sacs, causing friction and tearing.

Infection: Many common bacteria can infect the bursae.

Symptoms and Complications

The essential symptom of bursitis is pain, localised near the joint. The pain is likely to be worse when you make unaccustomed movements or strain the joint muscles. Many other diseases can cause joint pain, however, so it's important that you see a health care professional for a proper diagnosis.

Bursae that are near the skin surface, like the knee and elbow, may cause visible redness and swelling when they are inflamed. Very red, hot skin and extreme pain is often a sign either of crystals or of a bacterial infection.

Severe or long-lasting bursitis of the shoulder, for example, can lead to reduced movement or use of the joint and result in muscle atrophy (wasting). Permanent changes in the shape of the bursa, such as thickening or enlarging can occur and the surrounding tissues can become chronically inflamed.

Making the Diagnosis

Before making a diagnosis of bursitis, a number of possibilities need to be ruled out. Muscle injuries, joint injuries, local internal bleeding, synovitis, and cellulitis can all cause bursitis-like symptoms. Your doctor may ask you to take tests for rheumatoid arthritis and osteoarthritis.

If the joint is hot, red, and swollen, your doctor will want to check for bacteria. It's vital to know if the bursa is infected, because the standard treatment for noninfectious bursitis does not treat infection and in some situations may suppress the immune system.

Treatment and Prevention

A mild bout of bursitis that is not caused by bacteria is usually treated with rest or a splint, ice packs, or acetylsalicylic acid* (ASA) or other anti-inflammatory medications. Physiotherapy treatments like ultrasound may be helpful. If that doesn't work, an injection of corticosteroids mixed with local anaesthetic may be tried. These medications are injected directly into the bursa.

Corticosteroids are potent anti-inflammatories and steroid injections usually take care of the inflammation. If corticosteroid injections don't help, the same medication might be given in pill form. It's never given to people with bacterial infection. Bacterial infections are treated with antibiotics.

Sometimes your doctor will draw some fluid out with a needle. Crystals may remain, but large clumps can be removed surgically or by needle.

It's vital to exercise the joint when you're recovering from bursitis. Your doctor or therapist will give you a detailed plan, depending on which joint is used and the degree of muscle atrophy. Physiotherapy and ultrasound are other types of treatment your doctor may suggest.

*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For more information on brand names, speak with your doctor or pharmacist.