Bursitis refers to a condition, which involves the swelling and inflammation of a bursa. The bursae are the fluid-filled sacs, that can form under the skin, typically over joints, and act as cushions between bones and tendons. The primary symptoms of this problem include swelling, tenderness, and pain within the affected area. Almost any bursa in the body can become inflamed, but this issue occurs most commonly in the elbow, shoulder, hip, and knees.