What is Bursitis

Dear Ask The Doctor: What is bursitis?

Dear Mary John: Bursitis is inflammation of a bursa caused by repetitive use, trauma, infection, or systemic inflammatory disease. Bursae are flattened sacs that serve as a protective buffer between bones and overlapping muscles (deep bursae) or between bones and tendons/skin (superficial bursae). These synovial-lined sacs are filled with minimal amounts of fluid to facilitate movement during muscle contraction. Deep bursae, such as the subacromial (shoulder) and iliopsoas (hip) bursae, are located in the fascia. Superficial bursae, such as the olecranon(elbow) and prepatellar bursae(knee), are located in the subcutaneous tissue. Humans have approximately 160 bursae. Bursitis most commonly affects the subacromial, olecranon, trochanteric, prepatellar, and infrapatellar bursae. Symptoms of bursitis may include localized tenderness, swelling, redness, and/or reduced /limited movement.