Your bone density test results are reported in two numbers: T-score and Z-score.

T-score

Your T-score is your bone density compared with what is normally expected in a healthy young adult of your sex. Your T-score is the number of units — called standard deviations — that your bone density is above or below the average.

T-score What your score means
-1 and above Your bone density is considered normal.
Between -1 and -2.5 Your score is a sign of osteopenia, a condition in which bone density is below normal and may lead to osteoporosis.
-2.5 and below Your bone density indicates you likely have osteoporosis.

Z-score

Your Z-score is the number of standard deviations above or below what's normally expected for someone of your age, sex, weight, and ethnic or racial origin. If your Z-score is -2 or lower, it may suggest that something other than aging is causing abnormal bone loss. If your doctor can identify the underlying problem, that condition can often be treated and the bone loss slowed or stopped.

Aug. 21, 2014