A 42-year-old woman had an inexplicable right ankle fracture that took 5 months to heal. We may all be wondering, 42 years old? No obvious history of trauma and it took 5 months to heal? In fact, this is a breast cancer patient who is on oral endocrine medication, and because of her youth, she did not have a bone density test, and the fracture occurred in a confusing way, and the healing time was significantly longer. Therefore, all patients who are taking oral endocrine drugs for breast cancer, especially those who are taking oral aromatase inhibitors, must have regular bone density check because the degree of osteoporosis also varies, and the intensity of treatment varies for different degrees. Knowing your degree and choosing the corresponding treatment drugs can reduce the degree of osteoporosis and can actively prevent the occurrence of fracture.