Bone mineral density (BMD)
DEKnochenmineraldichte (KMD)
Bone mineral density (BMD) is the amount of mineral, mostly hydroxyapatite, packed into your bone, per unit area (g/cm²) or volume. It is most often measured at your lumbar spine and femoral neck by a DEXA scan. The T-score compares your BMD to the average peak of a healthy young adult. By WHO criteria, a T-score of −1.0 to −2.5 is osteopenia, and −2.5 or below is osteoporosis. Each one-SD drop in BMD roughly doubles your hip-fracture risk. BMD falls with age, and faster in women after menopause. The main things you can change are resistance and impact exercise, enough dietary calcium and vitamin D, and estrogen-related hormonal status. Hip fracture in older adults carries a 20 to 30% one-year death rate. That makes protecting your BMD a direct longevity target.
Last reviewed:
This definition is educational and is not medical advice, a diagnosis, or treatment. Talk to a doctor about any health decisions. Read our full medical disclaimer