One method of reporting the results of a bone density test. BMD is compared to two norms, "young normal" and "age-matched." Young normal, known as your T-score, compares BMD to optimal or peak density of a 30-year old healthy adult. Fracture risk increases as BMD falls below young-normal levels. Age-matched, known as your Z-score, compares the individual's BMD to what is expected in adults of the same age and body size.