The World Health Organization has developed definitions for low bone mass (osteopenia) and osteoporosis. These definitions are based on a T-score. The T-score is a measure of how dense a patient’s bone is compared to a normal, healthy 30-year-old adult.
Normal: T-score between 0 and -1 is considered a normal result.
Low bone mass (medically termed osteopenia): T-score between -1 and -2.5. This signifies an increased fracture risk.
Osteoporosis: T score less than or equal to -2.5) defines osteoporosis.