Osteoporosis BMD refers to Bone Mineral Density, or BMD, which is an auxiliary test for the clinical diagnosis of osteoporosis, and the level of BMD is measured by dual-energy X-ray bone resorption. The results are categorized into T-value and Z-value. T-value is usually observed because it is used to evaluate the bone mineral density of perimenopausal and postmenopausal women, and men over 50 years of age, and osteoporosis can be diagnosed if the T-value is less than -2.5. Z-value is used to evaluate the bone mineral density of men under 50 years of age, and premenopausal women.