T-Score

When you have a DEXA scan, the machine measures the mineral content in your bones and then calculates a T-score by comparing your result to a reference population of young adults at their peak bone density. A T-score of 0 means your bone density is exactly average for a healthy young adult; each unit below 0 represents one standard deviation less than that average.

The World Health Organization has established widely used diagnostic thresholds: a T-score of -1.0 or above is considered normal; between -1.0 and -2.5 indicates osteopenia (lower-than-normal density); and -2.5 or below is classified as osteoporosis. These numbers help your healthcare provider assess your fracture risk and decide whether intervention is appropriate.

It is worth knowing that the T-score is just one part of the picture. Your provider will also consider your age, fracture history, family history, and other risk factors when assessing your bone health. A related measure — the Z-score — compares your bone density to others your own age rather than to young adults, and it is used differently in clinical interpretation.

The T-score gives you a concrete, standardized way to understand where your bone density stands relative to a healthy benchmark. For postmenopausal women especially, knowing your T-score is an important step in catching bone loss before it leads to fractures — which can significantly affect quality of life and independence.

Osteoporosis often has no symptoms until a fracture occurs, which is why the DEXA scan and T-score are such valuable tools. Armed with your T-score, you and your provider can have an informed conversation about lifestyle strategies, supplements, and medications that may help protect your bones.