Bursitis occurs when the bursa sac is inflamed. A bursa is a thin fluid-filled sac that helps to reduce friction, and ease rubbing between tendons, bones, ligaments, and skin. There are about 160 bursae in the body, and the major ones are found in the hip, shoulder, elbow, and knee. Inflammation of the bursa is usually characterized by pain, redness, and swelling. Hip bursitis occurs when a bursa in the hip becomes inflamed. There are two bursae in the hip. One covers the bony point of the hip bone that is called the greater trochanter. Inflammation of this bursa is called trochanteric bursitis. The other bursa – iliopsoas bursa – is located on the inside of the hip (the groin area). When this bursa is inflamed, the pain is felt in the groin area. This condition is not as common as trochanteric bursitis, but it is treated the same way.