The Z-value of the bone density result indicates the ratio of the tested patient’s bone density to the average peak bone density of the same age and sex, and of the same race, that is, the comparison of the same condition population, and is generally recorded in standard deviation units. If the Z-value is greater than -2g/cm^3, it indicates that the BMD value of the tested patient is within the normal range for the same age group. If the Z-value is ≤ -2g/cm^3, it means that the BMD of the tested patient is lower than that of the normal peers. However, it is not possible to determine whether the patient has osteoporosis or bone condition simply by the Z value, but it is necessary to combine it with the T value of the bone density test at the same time, which is generally used clinically to determine whether the bone density of human body is normal or not. T value is a relative test value, which is a comparison between the bone density of the tested person and the bone density of a healthy young person aged 30-35, and if the T value is between (-1)-(1) g/cm^3, it means Bone density value is normal. If the T value is between (-1)-(-2.5) g/cm^3, it indicates low bone mass and bone loss, i.e. early osteoporosis. If the T value is below -2.5 g/cm^3, osteoporosis is diagnosed. If there is low bone mass or bone loss, medication is required.