I. Risk factors 1. Primary risk factors: falls, low bone mineral density, history of fragility fractures, age >65 years, family history of fractures. 2. Secondary risk factors: smoking, alcoholism, low body mass index, hypogonadism, early menopause (<45 years old), long-term malnutrition, history of drugs affecting bone metabolism (glucocorticoids, heparin, etc.), rheumatoid arthritis, hyperthyroidism, hyperparathyroidism. Hao Jie, Department of Orthopedics, The First Hospital of Chongqing Medical University, Chongqing, China Preventive measures 1. 2. Maintain moderate body weight. 3.Adhere to daily moderate muscle strength exercise and whole body balance and coordination exercise. 4.Appropriate outdoor exercise, increase sunlight. 5.Take various measures to prevent falls. 6.Preventive and correct use of medication.