Inflammation within a BURSA. ACUTE bursitis is usually the result of injury, especially on the knee or elbow, when the prominent part of the joint becomes swollen, hot, painful and red.

CHRONIC bursitis is due to too much movement of, or pressure on, a bursa, with fluid building up therein. Fluid may need to be drained and the affected area rested. Excision of a chronically inflamed bursa is sometimes necessary. For example, housemaid's knee is a chronic inflammation of the patellar bursa in front of the knee, due to too much kneeling.

Chronic bursitis affecting ligaments round the wrist and ankle is generally called a GANGLION.