Updated August 31, 2015.
Every person has hundreds of bursa found throughout the body. The function of a bursa is to decrease friction between two surfaces that move in different directions. The bursa is a slippery, fluid-containing sac. Normally, the bursa is thin and contains a small amount of fluid.
A bursa is found where there is movement of a joint causing two tissues to rub against each other. For example, behind the elbow or in front of the knee, there is a bursa to allow the skin to move without rubbing against the bone.
These movements should be smooth and effortless.
Bursitis - Inflammation of the Bursa
Under normal circumstances, the bursa provides a slippery surface that has very little friction with movement. Bursitis means that the bursa has become inflamed. The bursa loses its gliding capabilities, and becomes more and more irritated when it is moved.
When the condition called bursitis occurs, the normally slippery bursa becomes thickened and swollen. The added bulk of the swollen bursa causes more friction within an already limited space. Also, the smooth gliding bursa becomes gritty and rough. Movement of an inflamed bursa is painful and irritating.
Signs of Bursitis
Bursitis typically results from a repetitive overuse injury or due to prolonged pressure applied directly to the bursa. The next most common cause of bursitis is an acute injury, such as a contusion. Systemic inflammatory conditions, such as rheumatoid arthritis and gout, may also lead to bursitis. The last major cause of bursitis is infection.
An infected bursitis, also called a septic bursitis, occurs when there is infection within the bursa. There is usually a break in the skin over the bursa that causes the infection, but there can also be infection spread to the bursa from within the body.
Bursitis is almost always diagnosed on physical examination. Findings consistent with bursitis include:
- Tenderness directly over the bursa
- Pain with movement of overlying muscles and tendons
- Swelling of the bursa
If there is a suspicion of infection, your doctor may obtain some of the fluid from the swollen bursa for microscopic analysis. The fluid can usually be suctioned from the bursa with a small needle and a syringe.
Imaging tests such as x-rays and MRIs are not usually needed to make the diagnosis of bursitis, but may be performed to ensure there is no other problem, such as a fracture, that could be causing the symptoms of pain and swelling.
If you have any sign of infection associated with bursitis you should alert your doctor immediately. These signs of infection include:
- Open wounds around the area of bursitis
- Redness of increasing warmth the skin
- Systemic signs of infection such as fevers, chills, and sweats
Treatment of Bursitis
Treatment of bursitis depends on the specific type of bursitis, but the general focus is to rest the bursa, decrease inflammation, and allow time for recovery. Most all cases of bursitis will recovery with non-surgical management. When the bursitis is persistent despite appropriate treatment, surgical excision of the bursa is an option. In people diagnosed with infection of the bursa, a septic bursitis, there will also need to be appropriate antibiotic treatment.
Sources:
Aaron DL, et al. "Four Common Types of Bursitis: Diagnosis and Management" J Am Acad Orthop Surg June 2011 ; 19:359-367.