1, postmenopausal women: postmenopausal estrogen levels decline, resulting in increased bone resorption, is one of the important causes of osteoporosis. Zou Haibo, Department of Spine Surgery, China-Japan Friendship Hospital, middle-aged and elderly people: the dysregulation of the secretion of calcium-regulating hormones leads to disorders of bone metabolism, in addition, the reduction of digestive function and outdoor exercise are important reasons why the elderly are prone to osteoporosis. 2, how to prevent osteoporosis in the elderly: osteoporosis in the elderly, prevention is more important than treatment, the focus should be to prevent further rapid bone loss, to protect the fragile bone. And to maintain a good quality of bones, we must start from the daily habits of life. (1) appropriate participation in sports moderate exercise is beneficial to the health of muscles and bones, can improve muscle tone and elasticity, enhance the tolerance of bones, increase the amount of bone bleeding, so that good bone nutrition, delay the aging of bones. The elderly should pay attention to the amount of exercise, exercise in moderation, too much, too little is not appropriate; and to pay attention to safety, the time of exercise should be selected in the time of light. Secondly, we should choose a good sports venue, should be familiar with the environment, do not choose a place where there are young people in strenuous activities at the same time, in order to avoid damage caused by the impact. (2) pay attention to reasonable nutrition calcium is necessary to maintain the strength of the bones, calcium-rich foods help the balance of calcium metabolism, facilitate the deposition of bone minerals, adequate protein helps the formation of bone matrix. The amount of calcium in the diet of the elderly is often inadequate, which is related to factors such as reduced food intake, poor appetite and reduced digestive function, so attention should be paid to the intake of calcium-rich foods, such as milk and eggs can provide high-quality protein, but also rich in calcium and phosphorus. Others are green vegetables, beans and soy products, fish and shrimp, seafood plants, shellfish, etc. The intake of various vitamins is also important for the prevention and treatment of osteoporosis. (3) Prevent falls The bones of the elderly become fragile because of osteoporosis, but as long as they are well protected, they are like a glass that will not break without crashing to the ground, so preventing falls is an important measure to prevent fractures caused by osteoporosis. (4) cultivate good habits to prevent osteoporosis: smoking can increase the acidity of the blood to make bone dissolution; drinking too much alcohol, too often can lead to increased endocrine hormones of osteolysis, so that calcium is lost from the urine, are examples of contraindications. If you are optimistic and open-minded, your movements and thoughts will be agile, which will help strengthen your neural response and balance, thus reducing the occurrence of fractures. If you have a disease or pain, you should seek medical attention. Many endocrine diseases, myeloma and leukemia can cause osteoporosis. Some drugs can promote osteolysis. Such as prednisone, heparin and the like should be used with reasonable caution. Aging is an irresistible law of nature, and bone tissue is no exception, and will become lax with age, but as long as we are good at self-care, we can completely delay and reduce the occurrence of osteoporosis.