Bursitis is an inflammation of the greater trochanteric bursa. This is a small pillow-like structure that sits in between the greater trochanter of your femur and its connective tissues at the outside of your hip. It acts as a shock absorber and protective barrier between a bony prominence on your femur (greater trochanter) and the overlying tendons and muscles. It gets irritated and inflamed from repetitive pressure and rubbing from the overlying tissues. In addition, the gluteus medius tendon that runs right over the bursa can also be inflamed.  Sometimes the tendon can get inflamed and the bursa is fine. Regardless of which structure is inflamed, the treatment is the same.