bursitis, acute or chronic inflammation of a bursa, or fluid sac, located close to a joint. In response to irritation or injury the bursa may become inflamed, causing pain, restricting motion, and producing more fluid than can be absorbed readily. An attack of bursitis usually causes great pain and tenderness in the affected area. Common areas of involvement include the shoulder and big toe (see bunion). Depending on the cause and the degree of involvement, bursitis is treated with nonsteroidal anti-inflammatory drugs (NSAIDs), antibiotics, corticosteroids, and immobility until the pain subsides. Superficial bursas, not necessary to the function of a joint, or bursas that have become calcified, may be excised.

Inflammation of the lubricating sac (bursa) over a joint or extension of a joint, or between tendons and muscles or bones, caused by infection, injury, arthritis or gout, calcium deposits along a tendon or joint, or repetitive minor irritation. Common types are “housemaid's knee,” “soldier's heel,” “tennis elbow,” and “weaver's bottom.” Bursitis in the shoulder is the most common form. Usually occurring in people unaccustomed to physical labour, it may be so painful that the affected part cannot be used. Treatment includes rest, heat, mild exercise, and medication to relieve inflammation and remove calcium deposits.

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