Bone mass is measured by dual-energy X-rays. Normal bone mass is generally defined as a measured value of (-1) or more. Decreased bone mass refers to a measurement between (-1) and (-2.5), and osteoporosis refers to a bone mass below (-2.5). A bone mass above (-1) is normal and does not require special treatment. If the bone mass decreases, it is usually seen in postmenopausal women or middle-aged and elderly patients, and it is generally recommended to supplement calcium ions, eat more high-calcium foods, perform appropriate physical function exercises, and get more sunlight. If the standard of osteoporosis is reached, in addition to active calcium supplementation, anti-osteoporosis treatment should also be actively carried out, which means that drugs against bone resorption, such as zoledronic acid, should be used to prevent the loss of bone mass.