Meanings of T-scores of bone mineral density (BMD) test.

Healthcare providers use the T-score to diagnose osteoporosis. If more than one bone is tested, they use the lowest T-score to make a diagnosis of osteoporosis. The

World Health Organization (WHO) has defined the T-scores and what they mean.
What your T-score means:

A T-score between +1 and -1 is normal bone density. Examples are 0.8, 0.2 and -0.5.

A T-score between -1 and -2.5 indicates low bone density or osteopenia. Examples are T-scores of -1.2, -1.6 and -2.1.

A T-score of -2.5 or lower is a diagnosis of osteoporosis. Examples are T-scores of -2.8, -3.3 and -3.9.

The lower a person’s T-score, the lower the bone density. A T-score of -1.0 is lower than a T-score of 0.5; a T-score of -2.0 is lower than a T-score of -1.5; and a T-score of -3.5 is lower than a T-score of -3.0.

For most BMD tests, 1 SD difference in a T-score equals a 10-15 percent decrease in bone density. For example, a person with a T-score of -2.5 has a 10-15 percent lower BMD than a person with a T-score of -1.5.

Source of Information: http://www.nof.org/osteoporosis/bmdtest.htm ( by National Osteoporosis Foundation of USA)