How is osteoporosis diagnosed?

Osteoporosis is diagnosed by bone mineral density (BMD) of the spine or hip, which is measured with dual energy x-ray absorptiometry (DEXA) scans. A normal BMD is no more than 1 standard deviation (SD) below the average or reference value. Osteopenia (low bone mass) is 1-2.5 SDs below the reference and osteoporosis is 2.5 SD or more below the reference BMD value.^[1]