DEXA Bone Density Scan: Cost, Process and What Your T-Score Means

A DEXA scan measures how dense your bones are, usually at the hips and lower spine, using two very low-energy X-ray beams. You lie on a padded table fully clothed while a scanning arm passes over you. It takes around ten to fifteen minutes, the radiation dose is smaller than a chest X-ray, and it is the standard test for diagnosing osteoporosis.

This article is general information, not medical advice. If you are worried about your bones or have had a fracture, speak to your GP.

What the scan measures, and where

DEXA stands for dual-energy X-ray absorptiometry — two X-ray energies passed through the body, with the difference between how each is absorbed used to separate bone from soft tissue. It produces a number, bone mineral density, rather than a picture you would recognise.

The Royal Osteoporosis Society describes the scan as a scanning arm passing over your body taking images of your spine and hips, the two most common places where bones break, with the wrist sometimes added. Those sites are chosen because they predict fracture, not because they are convenient.

There is no tunnel and nothing encloses you. If you found an MRI difficult, DEXA is a completely different experience: an open table, a low arm moving slowly above you, and a request to keep still.

The radiation dose, in proportion

People overestimate this one badly, usually because the word X-ray does the work. The International Atomic Energy Agency's guidance on radiation protection during DXA puts the effective dose for a spine plus femur scan at under 1 microsievert to about 15, depending on the equipment — pencil-beam systems at the low end, fan-beam systems from roughly 1 to 10.

For comparison, the same IAEA source gives a chest X-ray as 20 to 50 microsieverts, and natural background radiation as around 10 microsieverts a day. The Royal Osteoporosis Society puts it plainly: the amount of radiation is similar to what you would get from three days of normal life.

That is a genuinely small exposure. It is still not zero, which is why DEXA is not sold as something to have annually for interest. Our X-ray cost guide covers dose comparisons for other plain imaging.

What a T-score means

Your result is not reported as a raw density figure for you to interpret. It is reported as a T-score: how far your bone density sits above or below the average peak density of a healthy young adult, counted in standard deviations.

These thresholds come from the World Health Organization classification, and the International Society for Clinical Densitometry's official positions confirm they apply to postmenopausal women and men aged 50 and over, measured at the femoral neck, total hip or lumbar spine.

A minus sign is not a verdict. Osteopenia is a description of a measurement, not a disease, and plenty of people with a T-score of -1.5 will never fracture.

What a Z-score means, and who gets one

The T-score compares you with a young adult. That comparison stops being useful for a 34-year-old woman or a 42-year-old man, because everyone's density declines with age and a low T-score would tell you little.

For those groups the Z-score is used instead: the same measurement, compared against people of the same age, sex and ethnicity. The ISCD's official positions state that Z-scores are preferred for premenopausal women and men under 50, and that this distinction is particularly important in children. A Z-score of -2.0 or lower is described as below the expected range for age, while anything above -2.0 is within it.

A Z-score below the expected range usually prompts a search for a cause — a medication, a hormonal condition, a malabsorption problem — rather than a straight diagnosis of osteoporosis. That is a conversation for a clinician.

Density is only part of the answer

This is the point private bone-density marketing tends to skip. The Royal Osteoporosis Society is explicit that bone density scan results do not give a complete picture of bone strength, and that treatment decisions use fracture risk assessment alongside the scan.

In the UK, that assessment is FRAX. The National Osteoporosis Guideline Group recommends FRAX assessment for any postmenopausal woman, or man aged 50 or over, with a clinical risk factor for fragility fracture — previous fracture, parental hip fracture, smoking, glucocorticoid use, alcohol intake of three or more units daily, rheumatoid arthritis, diabetes, and others. NOGG also lists triggers beyond the FRAX inputs, including height loss of 4cm or more, thoracic kyphosis, falls and frailty, and treatments such as aromatase inhibitors or androgen deprivation therapy.

FRAX gives a 10-year probability of hip fracture and of major osteoporotic fracture, and the density result feeds into it. A scan result without that context is a number in search of a meaning.

What a private DEXA costs

DEXA is one of the cheapest scans on the private market and one of the least advertised, which is an odd combination. Checking UK providers' own published prices in September 2026, private DEXA ran from about £115 to £145 at independent London imaging centres — well under the cost of a single-region MRI.

Two things to check before booking. First, whether the price includes a consultant radiologist's report, or only the scan. Second, which sites are included: a hip and spine study is the standard, and a cheaper quote covering one site only is not the same test. Prices were checked in September 2026 and change, so treat these as market ranges rather than a quote.

Worth separating from all of this: the body-composition DEXA sold by gyms and longevity clinics measures fat and lean mass. It uses the same machine but answers a different question, and it is not a bone density diagnosis.

Frequently asked questions

Do I need a GP referral for a private DEXA scan? Some independent centres accept self-referral and some require a referral. Because the result needs FRAX and clinical context to mean anything, having a referrer who will act on it is more useful than it might sound.

Can I have a DEXA scan if I am pregnant or might be? Tell the clinic before you attend. Any decision about imaging in pregnancy is made by the clinic's radiographer against their own protocols, not from general advice.

Will a recent barium study or contrast scan affect it? It can. Residual contrast in the abdomen interferes with the spine measurement, so clinics usually ask you to wait. Mention any recent CT with contrast, nuclear medicine study or barium test when you book.

Is a heel ultrasound the same thing? No. Peripheral tests at the heel or wrist are screening tools and do not carry the WHO diagnostic classification, which is based on hip and spine DXA.

If you want to see which centres near you offer bone density scanning, you can search DEXA providers on FindScan or browse everything available in your area. If you are booking, our scan preparation guide covers what to wear and bring.