Aromatase inhibitors are anti-estrogenic drugs, and the commonly used aromatase inhibitors are exemestane, letrozole and anastrozole. Its harmful effects mainly include osteoporosis, dyslipidemia, and joint pain. 1. Osteoporosis: Aromatase inhibitors will make androgens cannot be converted into estrogen, inhibit estrogen synthesis, and a decrease in estrogen level will lead to a decrease in free calcium concentration in the blood, loss of bone mass and thus lead to osteoporosis, which can lead to bone fracture if the degree is serious. 2. Dyslipidemia: Decrease in estrogen level will lead to increase in LDL in blood, which is the main risk factor for atherosclerosis, and increase the prevalence of cardiovascular and cerebrovascular diseases. 3. Joint pain: aromatase inhibitors not only cause joint pain, but also cause pain in some musculoskeletal and other parts. When applying aromatase inhibitors, they should be standardized under the guidance of a doctor and follow the doctor’s instructions.