What Is a T-Score?
Your T-score compares your bone mineral density to that of a healthy 30-year-old adult — the age when bone density peaks. It's the standard metric used to diagnose osteoporosis.
- -1.0 or above: Normal bone density
- -1.0 to -2.5: Osteopenia (lower than normal bone density)
- -2.5 or below: Osteoporosis
These thresholds come from the World Health Organization. Your T-score is the number your doctor will focus on most when assessing fracture risk.
What Is a Z-Score?
Your Z-score compares your bone density to other people of the same age and sex. It answers a different question: is your bone density normal for someone like you?
- Above -1.0: Within expected range for your age
- Below -1.0: Lower than expected — may indicate an underlying condition affecting bone health
A low Z-score in a 45-year-old is more clinically significant than in a 75-year-old, because some bone loss is expected with age. A low Z-score can prompt your doctor to investigate secondary causes like vitamin D deficiency, thyroid issues, or medication side effects.
Why Both Scores Matter
Your T-score tells you where you stand relative to peak bone health. Your Z-score tells you whether your bone loss is expected for your age or something more is going on.
Together, they give your physician (and you) a complete picture of your bone health status and help guide decisions about treatment, supplements, and lifestyle changes.
How to Improve Your Bone Density
Weight-bearing exercise. Walking, running, and resistance training all stimulate bone growth. Your bones respond to mechanical stress by getting stronger.
Calcium and Vitamin D. These are the raw materials your body needs to maintain bone. Most adults don't get enough of either.
Monitor with DEXA. An osteoporosis screening scan at Desert Dexa gives you T-scores and Z-scores for your hips and spine — the areas most vulnerable to fracture. Track changes over time to see if your interventions are working.
Know your bone density numbers. Book an osteoporosis screening scan at our Rancho Mirage or San Dimas location.
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