The two most common causes of gluteus medius muscle pain include gluteus medius tears and trochanteric bursitis, notes UCSan Diego Health. The gluteus medius is one of the important muscles surrounding the hip, and it is part of the greater trochanter; a bony protrusion on the side of the hip in the upper thigh.
Trochanteric bursitis leads to pain and irritation to the gluteus medius, states UCSan Diego Health. Most people experiencing this condition have an irritation of the trochanteric bursa. In severe cases, the gluteus medius tears, leading to pain in the muscle. This condition is known as gluteus medius syndrome, and it causes inflammation on the outer part of the hip.