The main reason why people get shorter in old age is because the spine shortens. Causes of spinal shortening: (1) Thinning of the discs due to disc degeneration, which can lead to a reduction in height if several discs are involved. (2) Compression fractures of the vertebral body, caused by wedge-shaped changes in the vertebral body resulting in a reduction in height, which may eventually lead to hunchback or deformity. If a middle-aged or older person’s height is 2 cm lower than the previous year or 3 cm to 5 cm lower than when they were younger, they need to be alerted to the possibility of osteoporosis and a vertebral compression fracture.