The causes of hormonal osteonecrosis of the femoral head are not very clear now, after research can be divided into three main categories: 1. Osteonecrosis of the femoral head is due to long-term use of hormones causing abnormal fat metabolism. Abnormal fat metabolism will lead to abnormal metabolism of liver function, causing fat deposition in the liver, thus causing hyperlipidemia in the whole body. Hyperlipidemia will cause an increase in the viscosity of blood vessels, which will easily lead to blockage of the blood vessels supplying the femoral head, thus causing ischemia of the femoral head and leading to necrosis of the femoral head; 2. Further can cause necrosis of the femoral head; 3. Long-term use of hormones can cause osteoporosis. Osteoporosis will lead to fracture of the femoral head trabeculae, which will further cause deformation and collapse of the femoral head, resulting in necrosis of the femoral head and affecting the function of the hip joint.