Medical conditions

Bursitis is the inflammation of a bursa (synovial sac), which functions as a membrane sac filled with fluid, and there are several bursae in the human body. The function of this sac is to prevent friction between two structures (for example, tendon and bone or tendon and muscle) or to protect bony prominences. Inflammation of the bursae causes pain when moving the joint and frequently causes local swelling (edema). In the hip, the bursa is located laterally over the greater trochanter. This injury may result from acute trauma or microtrauma caused by repetitive efforts. Symptoms include sharp pain in the lateral region of the hip, aggravated by pressure over the bony prominence of the greater trochanter. The pain may radiate down the lateral side of the thigh, generally not extending below the knee, and worsens when lying on the affected side.