What is the normal reading for this?
Bone density is calculated by comparision to the mean value for young adults–called the T score. The World Health Organization has defined a T score of less than -2.5 (2.5 standard deviations below the mean) as osteoporosis, -1.0 to
-2.4 as osteopenia. Decision to treat depends on your risk factors and if your score is worsening. Prior fractures or loss of height also are reasons to treat. See the section on soteoporosis on this website.