Bursitis is inflammation of a bursa — a small fluid-filled sac that cushions bone and soft tissue. It commonly affects the elbow, outer hip, kneecap and shoulder. Most cases settle with simple measures, but an infected bursa needs prompt treatment.
Bursitis is inflammation of a bursa, one of the small fluid-filled sacs that cushion bones and the soft tissues around them. When a bursa is irritated by a knock, prolonged pressure, repetitive activity or a medical condition such as rheumatoid arthritis or gout, it fills with extra fluid, causing swelling and pain. Common sites include the tip of the elbow, the outer hip (usually as part of gluteal tendinopathy), the front of the kneecap, and the shoulder.
The most important first step is deciding whether the bursa is infected. A red, hot, increasingly painful bursa — especially with fever — may be a septic bursa, which is assessed promptly, drained and treated with antibiotics, and should not be injected with a corticosteroid. Fluid can be sampled to check for infection or gout, and ultrasound can help assess the bursa and guide any procedure.
Non-infected bursitis is usually managed with activity modification, padding or a splint, and simple analgesia or short-term anti-inflammatory medication. If it does not settle, the fluid can be drained and a corticosteroid injected. Because recurrent elbow or kneecap bursitis is often driven by pressure or kneeling, addressing the underlying activity and using protective padding is as important as treating the flare.