When women experience hip pain while sleeping on their side, they should consider whether there is a lesion or injury to the hip joint, most commonly due to inflammation of the bursa of the left hip joint, which can lead to pain in the hip joint when sleeping on their side under pressure. The inflamed bursa is located at the location of the femoral trochanter, which is near the topmost bone structure of the outer thigh, and when there is local inflammation, local pressure causes pain. If you press the area with your hand, the pain will be more obvious. If the inflammation is relatively serious, the pain will be more obvious when you move around the thigh and hip joint area, and swelling may occur locally. After rest, the pain can be relieved, and once the local pain occurs, it will affect the person’s walking. Once the above symptoms appear, the first thing to consider is whether there is hip bursitis. If the pain is not significantly worse when the hand is pressed near the protruding bone structure on the outer side of the top of the thigh, you should consider whether it is a lesion inside the hip joint, such as a lesion of the femoral head or an inflammation of the synovial membrane of the hip joint.