The hip is the most important part of retaining balance and posture. The primary purpose of the hip joint is to maintain the weight of the body standing still as well as in motion. The ball-and-socket hip joint is designed to withstand repeated motion and wear, however, the cartilage in the hip can become damaged due to age and use. The two main bones in the hip joint are the femur and the acetabulum (the concave surface of the pelvis). The acetabulum moves against the femoral head of the femur bone which permits our bodies to move.
Joints are the locations in your body where two bones meet. Movement of these bones against each other is what permits our bodies to move. Cartilage is located at the end of our bones and is a smooth, slippery tissue that allows the bones to slide against one another with minimal friction. Once cartilage is damaged, it cannot heal itself and the progressive deterioration leads to a loss of cartilage and exposed bone. Because pain sensors are located in bone and not in cartilage, it is the exposed bone that results in a painful joint.
As you might expect, there are many different reasons why your hip may be painful, including injury, infection, and arthritis.