Bone densitometry clinical indications: 1, women over 65 years of age and men over 70 years of age without other risk factors for osteoporosis; 2, women under 65 years of age and men under 70 years of age with one or more risk factors for osteoporosis; 3, male and female adults with a history of fragility fracture or (and) a family history of fragility fracture; 4, male and female adults with low levels of sex hormones from various causes; 5, those with existing osteoporotic changes on X-ray; 6, those receiving osteoporosis treatment for efficacy monitoring; 7, those with a history of diseases and medications that affect bone mineral metabolism.