How Long Does a Bone Density Scan Take? What to Expect

How long does a bone density scan take?

The scan itself usually takes about 10-20 minutes, and you're normally in and out of the department in around 20-30 minutes. A bone density scan — properly called a DEXA (or DXA) scan — is one of the quicker medical scans you can have.

The exact figure varies a little by clinic. The Royal Osteoporosis Society says a DEXA "takes around 20 minutes" and is "all done in about 20 minutes" Royal Osteoporosis Society, 2024. The Christie NHS Foundation Trust quotes "10 to 20 minutes" The Christie NHS, 2024, and Cambridge University Hospitals describes lying flat "for around 10-15 minutes while the scanner moves over you," with patients "usually only... in the department for 20-30 minutes" once check-in and positioning are counted Cambridge University Hospitals NHS, 2024.

So a safe expectation: the actual scanning is a matter of minutes, and the whole visit is well under an hour. There's usually a short questionnaire beforehand (about your height, weight and medical history) and a moment or two to get you positioned correctly — that's where the extra time goes, not the scan itself.

Does a bone density scan hurt?

No — a DEXA scan is completely painless and non-invasive. This is one of the most common worries, and it's an easy one to put to rest.

The Royal Osteoporosis Society is unambiguous: "You won't feel anything while the scan is in progress" Royal Osteoporosis Society, 2024. The NHS describes the scan as simply "quick and painless" NHS, 2024, and the Christie NHS Trust adds that it "should not feel unpleasant" The Christie NHS, 2024.

Crucially, there's nothing claustrophobic about it. Unlike an MRI, "you don't go into a tunnel or need an injection" — you simply lie on your back while the scanner does its work Royal Osteoporosis Society, 2024. There's no needle, no contrast dye and nothing enclosed around you.

What actually happens during the scan?

You lie on your back on a firm, padded couch, fully clothed, while a scanning arm passes slowly over your body — imaging your lower spine and one hip. That's essentially the whole procedure.

The Royal Osteoporosis Society describes the scanner arm slowly moving above you as it takes images of your hip, while you stay still on the couch Royal Osteoporosis Society, 2024. The scan usually focuses on the spine (lower back) and hip — the two sites where fractures cause the most harm Royal Osteoporosis Society, 2024. The main thing asked of you is to lie still so the images stay sharp; the radiographer may reposition a leg or arm to line up the joint properly.

If you want a fuller walk-through of what a bone-density appointment involves from start to finish, our guide to what a bone health assessment covers steps through it in detail.

Do I have to get undressed for a bone density scan?

Usually not — you normally stay dressed. The one thing that matters is avoiding metal, because it can interfere with the images.

The Royal Osteoporosis Society advises wearing "clothes without metal (such as zips, buttons and belts)" and notes that an underwired bra or a jeans zip may mean changing into a hospital gown, because "metal objects can affect the scan results" Royal Osteoporosis Society, 2024. The Christie NHS Trust simply suggests attending "in loose clothing without zips, buttons or fastenings" The Christie NHS, 2024, and Cambridge University Hospitals notes that if you wear metal-free clothing "it is not usually necessary to get changed" Cambridge University Hospitals NHS, 2024.

The practical tip: turn up in soft, comfortable clothes — leggings, a cotton top, no belt, no underwired bra, minimal jewellery. Do that and you'll almost certainly scan exactly as you are.

Is a DEXA scan safe — how much radiation is involved?

A DEXA scan uses a very low dose of X-rays — far less than a standard chest X-ray. It is X-ray-based, so it isn't radiation-free, but the dose is small.

Sources describe it in everyday terms rather than technical figures. The Royal Osteoporosis Society compares the dose to "the amount we would get from three days of normal life" Royal Osteoporosis Society, 2024, while the Christie NHS Trust likens it to "background radiation on a transatlantic flight" The Christie NHS, 2024. These are illustrative comparisons — the exact dose depends on the machine and the sites scanned — but they give a fair sense of the scale.

How long does it take to get your results?

Results aren't usually given on the day — they're reported afterwards, typically within a few working days to about three weeks depending on the provider. The scan is fast; the reporting takes a little longer.

On the NHS, the images are read and a report is sent back to the doctor who requested the scan. The Royal Osteoporosis Society says results are "usually available around three weeks after the scan" Royal Osteoporosis Society, 2024, and the Christie NHS Trust quotes "2 to 3 weeks" The Christie NHS, 2024. Private clinics tend to be quicker — as one example, Vista Health includes "a full report... available within three working days of the scan" Vista Health, 2025 — but turnaround genuinely varies by provider, so treat any single figure as a rough guide rather than a promise.

Is there a radiation-free alternative to a DEXA scan?

Yes — REMS is a radiation-free, ultrasound-based way to assess bone density and fracture risk, and it's the method Screen My Bones uses. It's designed to give a similar bone-health picture to DEXA without any X-rays.

REMS (Radiofrequency Echographic Multi-Spectrometry) is a non-ionizing technology — defined by "the absence of ionizing radiation" — that reads bone status from raw ultrasound signals. Published research describes REMS scans being "performed at both the proximal femur and lumbar spine using a 3.5 MHz convex ultrasound probe," estimating bone mineral density, providing a diagnostic classification, and offering T-scores shown to predict fragility fractures while also reflecting bone quality and microarchitecture PMC (REMS review), 2023. In other words, it looks at the same key sites as DEXA — the spine and hip — but with an ultrasound probe rather than X-rays. We compare the two head to head in REMS vs DEXA.

Because it uses no ionising radiation, REMS is well suited to people who want proactive checks or repeated monitoring over time without accumulating X-ray exposure.

What is a Screen My Bones REMS assessment day like?

It's a straightforward, radiation-free ultrasound scan delivered at a mobile pop-up near you — no hospital tunnel, no injection, no X-rays. You lie comfortably while a trained operator moves an ultrasound probe over the assessment sites, much like the gentle, painless experience of a DEXA scan, but without the radiation.

Screen My Bones runs these as "assessment days" — mobile pop-up clinics across the UK, rather than a fixed hospital department. If you'd like to know exactly how a visit unfolds, from arrival to leaving, our guide to what to expect at a screening day walks through it. And when you're ready, you can find and book a Screen My Bones assessment day near you.

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This article is part of our screening technology series.