a z-score compares your bone density to what is normal for someone your age. while a z-score alone is not used to diagnose osteoporosis in premenopausal women it can provide important information. here are some tips to help you understand your z-score: *if your z-score is above -2. 0 your bone density is considered within the ranges expected for your age or normal according to the international society for clinical densitometry (iscd). for example a z-score of 0. 5 -0. 5 and -1. 5 is considered normal for most premenopausal women. *if your z-score is -2. 0 or lower your bone density is considered below the expected range. examples are -2. 1 -2. 3 and -2. 5. if your z-score is in this range your health-care provider will consider your health history and possible causes of bone loss including secondary osteoporosis before making a diagnosis of osteoporosis. *if your z-score is normal but you've broken one or more bones from a minor injury your health-care provider may diagnose you with osteoporosis because some people with normal bone density break bones easily. as mentioned above a bone density test will also show a t-score. a t-score compares bone density to what is normal in a healthy 30-year-old adult.
at what age or point is the t-score in bone density scans used instead of a z-score?