Human height is a ruler that measures our growth and aging; it is also a mirror that reflects the health status of the human body. Starting from infancy, height grows gradually with growth and development, and generally reaches its peak at the age of 20-24. After middle and old age, height gradually decreases at a certain rate. However, not all height shortening is a normal physiological phenomenon. As we move into old age, a decrease in height is more likely to be the only symptom of osteoporosis. So what are the causes of height loss? When and to what extent is height loss abnormal? The causes of height reduction mainly include the following two aspects: 1. Due to disc degeneration resulting in disc thinning, a person’s height is reduced by involving several discs. This is an unpreventable and untreatable cause of height loss in old age. 2. Vertebral compression fractures and wedge-shaped changes in the vertebral body lead to height loss. It can eventually lead to hunchback or deformity. The famous foreign Baltimore Longitudinal Study of Aging found that, regardless of men and women, height begins to decline from the age of 30, and the rate of decline gradually accelerates with age. From the age of 30 to 70, the cumulative height decrease is about 3 cm for men and 5 cm for women. Then if an older person’s height is 2 cm lower than the previous year, or 3-5 cm lower than the maximum height in younger years, they need to be alerted to the possibility of osteoporosis and a vertebral compression fracture. Because 70% of vertebral compression fractures in older patients are painless, the only manifestation may be a decrease in height. The cause of vertebral compression fractures is osteoporosis, a condition that occurs in postmenopausal women and older men and is characterized by decreased bone density and destruction of the fine bone structure, resulting in increased brittleness of the bone and susceptibility to fracture. Osteoporotic fractures (also known as fragility fractures) are the most significant and dangerous complication of primary osteoporosis, occurring in the vertebrae, hip and wrist. Because of its high incidence, it affects the quality of life of the elderly, costs a lot of money in medical care, and is an important cause of disability and death in the elderly. Moreover, the risk of re-fracture after a single fracture is greatly increased, so timely treatment of patients with osteoporotic fractures is necessary as an effective way to prevent re-fracture, maintain current height and avoid disability. Therefore, detecting height changes is the easiest and most direct way for the elderly to determine for themselves whether there are potential skeletal health problems. Once an abnormality is detected, it can be examined by dual-energy X-ray absorptiometry (DXA) and combined with bone metabolism indicators, a clear diagnosis can be made and an appropriate treatment plan can be formulated. The elderly can be free from the threat of osteoporosis and its complications and enjoy a happy old age.