DEXA Scan Results and T-Score Explained: How to Read Your Bone Density Report

What is a T-score on a DEXA scan?

Your T-score is the number that compares your bone density to the average peak bone density of a healthy young adult of the same sex — and it's the figure used to diagnose osteopenia and osteoporosis. In other words, it doesn't ask "how does your bone compare to other people your age?" — it asks "how does your bone compare to bone at its strongest?" Royal Osteoporosis Society, 2024

A DEXA (also written DXA) scan measures bone mineral density using a very low dose of X-rays — the World Health Organization designates it the gold-standard test for measuring bone density. StatPearls, 2023 The dose is far lower than a standard X-ray — the Royal Osteoporosis Society compares it to about three days of ordinary background radiation. Royal Osteoporosis Society, 2024 The result is expressed as a T-score measured in "standard deviations" — how far above or below that young-adult average your bones sit. A negative number simply means below-average density.

What do the T-score numbers actually mean?

The World Health Organization sets three bands, and your T-score falls into one of them. StatPearls, 2023

• −1.0 or above — normal. Your bone density is within one standard deviation of the healthy young-adult average.
• −1.0 to −2.5 — osteopenia (also called low bone mass). Bone density is below average but not low enough to be classed as osteoporosis.
• −2.5 or below — osteoporosis. Bone density is 2.5 standard deviations or more below the young-adult average.

These same bands are described by the Royal Osteoporosis Society, which frames the "normal" range as roughly +1 to −1, low bone density from −1 to −2.5, and osteoporosis at −2.5 and below. Royal Osteoporosis Society, 2024

What's the difference between a T-score and a Z-score?

A T-score compares you to a healthy young adult; a Z-score compares you to people of your own age, sex and ethnicity. Both appear on most reports, but they answer different questions. NHS, 2024

The T-score is the diagnostic number for osteopenia and osteoporosis. The Z-score matters because bones naturally weaken with age, so comparing a 70-year-old to a 30-year-old peak will almost always look "low" — the Z-score strips age out of the picture. Royal Osteoporosis Society, 2024 That's why the Z-score is the more useful measure in children and younger adults, where age-adjusted comparison makes more sense. Royal Osteoporosis Society, 2024

There's one number to watch: a Z-score below −2.0 is unusually low for your age and should prompt your doctor to look for a secondary cause of bone loss — a medical condition or medication driving it — rather than assuming it's simply age. StatPearls, 2023

How do you read a typical DEXA report?

A standard DEXA report gives you separate T-scores for two of the most common fracture sites — your lumbar spine and your hip — and your diagnosis is usually based on whichever is lowest. StatPearls, 2023 Some scans also measure the wrist/forearm. It's common for the two sites to disagree — you might be normal at the spine but osteopenic at the hip — which is exactly why both are measured.

Your report compares your density both to a young healthy adult (the T-score) and, separately, to an adult of your own age, sex and ethnicity (the Z-score). NHS, 2024 Results are typically available within around three weeks. Royal Osteoporosis Society, 2024 If you're paying privately, turnaround is usually faster — one UK provider quotes a full report within three days, at a fixed fee of £145. Vista Health, 2026 For a fuller breakdown, see our guide to bone density scan costs in the UK. If you're weighing up your options, our guide to REMS vs DEXA scanning breaks down the practical differences.

Does an osteopenia result mean I'll break a bone?

Not necessarily — but "low bone mass" is not the same as "no risk," and this is where people most often misread their result. The counter-intuitive truth is that most fragility fractures happen in people whose bone density sits in the osteopenia range, not the osteoporosis range — roughly 48–56% of fractures in postmenopausal women occur at osteopenia-level density. StatPearls, 2023 That's simply because far more people have osteopenia than full osteoporosis.

This is why doctors never treat the T-score in isolation. The NHS uses your bone density result alongside a fracture-risk assessment. NHS, 2024 Tools such as FRAX combine your density with age, weight, previous fractures and other risk factors — so someone in the osteopenia band may be offered treatment while someone technically in the osteoporosis band may not. If you want to know what low bone density can feel like day to day, see our guide to the early signs of osteoporosis.

What should you do after you get your DEXA results?

Take the result to your GP or clinic and treat it as a starting point, not a verdict. Depending on your T-score and overall fracture risk, the Royal Osteoporosis Society outlines several possible next steps: Royal Osteoporosis Society, 2024

• Lifestyle changes — weight-bearing and resistance exercise, adequate calcium and vitamin D, stopping smoking and moderating alcohol.
• Blood or urine tests to rule out secondary causes of bone loss, especially if your Z-score is low for your age.
• An osteoporosis medicine if your calculated fracture risk is high enough to warrant it.
• A follow-up scan to monitor your bone density, typically in two to five years.

The follow-up scan matters most: a single reading tells you where you stand today, but the trend over time tells you whether your bones are stable, improving or declining. A proactive bone health assessment is built around exactly that — establishing a baseline you can measure future scans against.

Does a REMS scan give a T-score like a DEXA scan?

Yes — REMS produces the same T-scores and Z-scores as DEXA, plus an extra measure of bone quality, without using any radiation. REMS (Radiofrequency Echographic Multi Spectrometry) is a portable, radiation-free ultrasound scan of the lumbar spine and hip that calculates bone mineral density and classifies your bones as normal, osteopenic or osteoporotic using the same T-score framework. PMC systematic review, 2025

Where it adds something is the Fragility Score — a scale reported in validation studies as running from 0 (normal) to 100 (maximum fragility) that reflects bone microarchitecture and quality independently of density. PMC systematic review, 2025 Because density is only part of what makes bone break, this is potentially useful: in one study of 1,989 patients followed for around 3.5 years, the REMS Fragility Score predicted incident fragility fractures and outperformed both REMS and DXA T-scores at the task. Fragility Score validation study, 2023

These are findings from specific validation studies, not universal clinical thresholds, and REMS should be seen as producing comparable T-scores plus an additional bone-quality measure rather than a wholesale replacement for DXA in formal WHO diagnosis. Its practical advantage is that, with no radiation involved, it's well suited to repeated monitoring over time and to radiation-sensitive groups. PMC systematic review, 2025 If you'd like a radiation-free baseline you can safely repeat, you can book a Screen My Bones assessment.

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This article is part of our screening technology series.