A bursa is a filmy-colored sac that protects and cushions your joints. Bursitis means inflammation of one of your bursa sacs. The inflammation may result from arthritis in the joint or injury or infection of a bursa. Bursitis produces pain and tenderness and may limit the movement of nearby joints. You can get bursitis in your shoulders, elbows, hips, knees, heels and big toe. Injuries, overuse and repetitive stress are common causes of bursitis. Certain diseases, such as arthritis and gout, might also cause it. It sometimes occurs with tendinitis. You can usually treat bursitis with rest, ice, and medicines to ease pain and reduce swelling. Other treatments include ultrasound, physical therapy, steroid injections and, in rare cases, surgery. Stretching before you exercise, strengthening your muscles and resting when you do repetitive tasks might help prevent bursitis.