Bone Density Scan Test
A bone density scan measures the amount of calcium and other minerals in your bones to show how strong and thick they are. It helps diagnose low bone mass (osteopenia) and osteoporosis, predict fracture risk, and monitor treatment.
What this test measures
A bone density scan (DEXA or DXA) uses low-dose x-rays to measure calcium and other minerals in your bones. Bones with more minerals are denser, stronger, and less likely to break.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Lower-than-normal results
A lower T-score means higher risk of bone fracture. A T-score between -1.0 and -2.4 indicates low bone density (osteopenia). A T-score of -2.5 or less indicates osteoporosis.
Frequently asked questions
What is a bone density scan?
It is a low-dose x-ray that measures calcium and other minerals in your bones to show bone strength and thickness.
Why might I need a bone density scan?
It is used to diagnose osteopenia and osteoporosis, predict fracture risk, and see if osteoporosis treatment is working.
What do T-scores mean?
T-scores compare your bone density to a healthy young adult. A score of -1.0 or higher is normal, -1.0 to -2.4 means osteopenia, and -2.5 or less means osteoporosis.
What do Z-scores mean?
Z-scores compare your bone density to others of the same age, weight, sex, and ethnicity. They are used for premenopausal women, men under 50, and children.
How often should I get a bone density scan?
Your provider will recommend a schedule based on your fracture risk: every 2 years for high risk, every 3 to 5 years for moderate risk, and every 10 to 15 years for low risk.
Related lab tests
Sources
- MedlinePlus: Bone Density Scan — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.