Bursitis

Bursitis is the swelling and irritation of one or more of bursa, which are synovial fluid filled sacs that acts as a cushion between muscles, tendons, and joints to create a frictionless gliding surface that makes normal body movement painless. When bursitis occurs and bursa become inflamed, muscles can feel stiff and movement can become difficult and painful. Bursitis is most common in the shoulders, knees, elbows, and hips.