Bone Density Scan Preparation: A Practical UK Guide
Dr Alex Trevatt30 September 2026Updated 1 October 2026
Preparing for a bone density scan is usually straightforward, but the correct instructions depend on the examination and the provider. Many NHS bone-density appointments do not require fasting or changes to usual medicines. A whole-body protocol may use different preparation to make measurements more comparable. Your appointment letter and scanning team therefore take priority over any general checklist.
DEXA, also written DXA, uses low-dose ionising radiation to measure bone mineral density or, under a different protocol, to estimate body-composition compartments. It is not the same as MRI, and you do not enter a tunnel. The most useful preparation is to follow the local instructions, wear clothing without metal and tell the team about recent contrast imaging, nuclear medicine and any possibility of pregnancy.
Table of Contents
- Standing in the Car Park Before Your First DEXA Scan
- What to Wear and What to Leave at Home
- Medications, Supplements, Food and Drink
- Timing Rules That Can Catch You Out
- What the Scan Itself Feels Like
- How Your Results Are Reported and Read
- After the Scan, Building a Sensible Plan
Standing in the Car Park Before Your First DEXA Scan
The person waiting outside the clinic may be wondering whether breakfast, a regular tablet or a metal zip has ruined the appointment. For a typical NHS hip-and-spine examination, the answer is often reassuring. The NHS guide to what happens during a DEXA scan says no special preparation is needed, although clothing with metal fasteners may need to be removed and a gown may be offered.
A clinical bone-density scan commonly measures the hip and lumbar spine. It can contribute to osteoporosis and fracture-risk assessment when a clinician has identified an appropriate medical question. The referral does not itself diagnose osteoporosis, and the scan result is interpreted with age, fracture history, medicines and other clinical risk factors.
The preparation that matters
Before leaving home:
- Read the appointment instructions: Local rules can differ for food, supplements, arrival time and recent imaging.
- Keep prescribed medicines unchanged unless told otherwise: Do not stop or alter treatment simply because a scan is booked.
- Choose simple, metal-free clothing: This can reduce the need to change into a gown.
- Report recent imaging: Tell the department about barium, oral contrast or a nuclear medicine examination.
- Raise pregnancy concerns before travelling: DEXA uses ionising radiation, so possible pregnancy needs to be assessed before exposure.
- Bring relevant information: The clinic may ask about medicines, fractures, operations, implants and earlier scans.
Clear pre-appointment communication helps people arrive with the right information. The protected Recepta.ai article on patient experience is a commercial practice-operations article, not clinical DEXA guidance, but its broader point about giving patients clear instructions is relevant.
What to Wear and What to Leave at Home
Loose, comfortable clothing without metal around the area being scanned is the simplest choice. Plain joggers, leggings or elasticated trousers and a T-shirt are often practical. Avoid zips, underwires, hooks, buckles, metal buttons, rivets and metallic decoration where possible.
Do not worry if every garment is not metal-free. Scanning departments can usually provide a gown or ask you to remove an item. What matters is that metal does not overlap the area being measured.
Why metal causes difficulty
Metal is mainly a measurement problem, not a sign that the scan has suddenly become dangerous. A dense object in the field can create an artefact, obscure anatomy or interfere with the software’s analysis. The team may therefore ask you to remove:
- jeans with metal rivets or buttons;
- an underwired bra or clothing with metal clasps;
- a belt, keys, coins, phone or wallet;
- jewellery or a watch if it lies near the measurement area;
- a garment with a zip across the hip, abdomen or spine.
A wedding ring can often remain in place when the hand is not being scanned, but the operator should decide. Implants, previous surgery and joint replacements are different from removable metal and should be disclosed rather than treated as something the patient can solve alone.
The source includes a protected legacy catalogue route labelled Demo DEXA Scan, which currently redirects to a Telomyx product page. A product label does not establish that an exposure is suitable or medically justified, and it should not be used as preparation guidance.
Medications, Supplements, Food and Drink
There is no single food and supplement rule for every DEXA appointment. Typical NHS bone-density guidance often permits normal food, drink and prescribed medicines. Some departments add a specific calcium restriction. Whole-body services may use a fasting protocol to reduce short-term variation in body-composition measurements.
That distinction explains why apparently contradictory instructions can both be correct for their own setting:
| Setting | Typical instruction | What to do |
|---|---|---|
| NHS hip-and-spine bone-density scan | Often no special preparation | Follow the appointment letter and contact the department if anything is unclear |
| A centre with a calcium protocol | Pause calcium supplements for the stated period | Follow that centre’s exact timing rather than applying it to every medicine |
| Telomyx whole-body DEXA appointment | The current pre-scan film says to fast for four hours, with water permitted | Follow the instructions supplied for that appointment |
The Telomyx film showing what happens at a DEXA appointment is specific to that service. It should not be used to overwrite the instructions for an NHS or another private provider’s examination.
Continue prescribed medicines unless the referring clinician or scanning team has told you differently. A list of medicines and supplements can help the operator record relevant details. Do not stop bisphosphonates, hormone therapy, thyroid treatment, blood-pressure treatment or any other prescribed medicine on the basis of a general online article.
The calcium exception
Dorset County Hospital’s DXA guidance asks patients not to take calcium supplements for 24 hours before the scan, while advising them to eat and drink normally and continue prescribed medicines apart from calcium supplements. This is a clear local instruction, not proof that every centre uses the same interval.
If calcium is part of a combined prescribed product, or if the appointment letter and medicine label seem to conflict, contact the department rather than guessing. Ordinary dietary calcium is not the same as a supplement restriction unless the provider explicitly says otherwise.
Timing Rules That Can Catch You Out
Recent barium, oral CT contrast or a nuclear medicine tracer can interfere with interpretation. The relevant interval varies by substance, examination and provider. Cambridge University Hospitals’ DXA attendance guidance asks patients to contact the department if they have had a barium X-ray, a CT scan involving a contrast drink or a nuclear medicine scan during the previous two weeks.
Do not assume that every injection or X-ray requires cancellation. Give the scanning department the exact examination, date and, if known, contrast or tracer used. The team can decide whether the appointment should proceed or move.
Pregnancy screening and repeat testing
Pregnancy or possible pregnancy must be disclosed before DEXA because it uses ionising radiation. Do not wait until you are lying on the scanner to mention it. The operator needs enough information to apply the service’s pregnancy procedure and decide whether the exposure should be postponed or reconsidered.
Under the UK guidance to the Ionising Radiation (Medical Exposure) Regulations, every exposure must be justified before it takes place. The practitioner considers the objective, the person’s characteristics, the expected benefit and detriment, and suitable alternatives that do not use ionising radiation.
Repeat scans are not automatically due because a fixed number of months has passed. The Royal Osteoporosis Society guide describes two to five years as a normal follow-up range for people who need another medical bone-density scan. That is not a universal timetable. Current professional positions say timing should be individualised and the result should be likely to influence management.
For clinic operators, the protected Call Loop scheduling article discusses reminders and missed appointments in commercial operational terms. It does not determine whether a DEXA exposure is justified or when a clinical repeat is appropriate.
A VO2 Max Test answers a separate question about aerobic capacity during graded exercise. It cannot replace bone-density assessment, and its preparation rules should not be transferred to DEXA.
What the Scan Itself Feels Like
A diagnostic bone-density scanner is open rather than tunnel-shaped. You lie on a flat table while a scanning arm passes over the relevant area. NHS guidance gives a typical scan time of 10 to 20 minutes, although the complete appointment can take longer for check-in, questions, changing and positioning.
For a lumbar-spine measurement, the operator may place the lower legs on a padded block to help position the spine. For a hip measurement, a support can hold the leg in the required rotation. Tell the operator if pain, stiffness or limited mobility makes a position difficult. Good positioning matters, but it should not be achieved by forcing a painful movement.
The protected Telomyx guide to how long a DEXA scan takes explains the difference between scan time and total visit time. Your appointment confirmation remains the better source for the time to allow on the day.
Stillness matters more than effort
DEXA is painless for most people. There is no injection for a standard examination, and the scanner does not enclose the body. The main task is simply to remain still when asked so movement does not blur the acquisition or reduce comparability.
Different protocols use different positions. A hip-and-spine examination, a forearm measurement and a whole-body acquisition are not interchangeable. Whole-body DEXA can estimate fat mass, lean soft tissue and bone mineral content, but it is not a diagnostic substitute for a clinically indicated hip-and-spine osteoporosis assessment.
After the scan, you can usually leave without recovery time. Do not expect the operator to diagnose osteoporosis at the table. Hospital results normally return through the referrer or reporting service. Telomyx analyses results after the visit and sends a detailed personal report within two working days rather than providing a same-day DEXA interpretation.
How Your Results Are Reported and Read
A bone-density report may contain images, bone mineral density values and reference scores. The purpose of the examination determines what those values can answer. A diagnostic hip-and-spine examination can contribute to osteoporosis classification and fracture-risk assessment. A whole-body composition report measures different regions and cannot independently diagnose osteoporosis.
Three terms with different jobs
The T-score compares bone mineral density with a young-adult reference. It is generally the preferred score for postmenopausal women and men aged 50 or older. The Z-score compares bone mineral density with an age-matched reference and is generally preferred before menopause, in men younger than 50 and in children.
FRAX estimates the 10-year probability of hip fracture and major osteoporotic fracture from clinical risk factors, with femoral-neck bone mineral density included when available. It supports clinical assessment but cannot contain every relevant factor or replace professional judgement.
| Score or tool | Comparison or input | Main role | Important limit |
|---|---|---|---|
| T-score | Young-adult reference | Diagnostic classification at appropriate central sites in relevant adult groups | A category does not determine treatment by itself |
| Z-score | Age-matched reference | Identifies whether bone density is below the expected range for age | It is not an independent diagnosis of osteoporosis |
| FRAX | Clinical risk factors, with optional femoral-neck BMD | Estimates 10-year fracture probability | It omits some risk detail and requires clinical judgement |
The International Society for Clinical Densitometry adult positions distinguish T-score and Z-score use and state that follow-up intervals must be individualised. The National Osteoporosis Guideline Group guidance explains how FRAX, clinical risk factors and bone mineral density fit together in UK case-finding.
For a more detailed explanation of report terminology, see the protected Telomyx guide to BMD and DEXA results. A concerning result still belongs in a conversation with the referrer, GP or an appropriately qualified bone-health clinician.
After the Scan, Building a Sensible Plan
The next step depends on why the scan was performed. A medical bone-density report may lead to fracture-risk review, tests for a secondary cause, treatment discussion or no immediate change. A body-composition report may inform a medically defined question, but it should not be translated into an osteoporosis diagnosis or a medication decision.
Medical follow-up and performance tracking are different
The UK government position published on 30 March 2026 states that non-medical DEXA for sports performance, general body-composition analysis and fitness profiling is prohibited under the current framework. An interest in body composition, weight management, fitness or sport may prompt an enquiry, but it is not itself the medical justification for exposure.
The Telomyx DEXA service follows a medically governed pathway. Every request uses a medical questionnaire, requires a referral and is individually justified by an entitled practitioner. If a person is unsuitable or the exposure cannot be justified, Telomyx does not issue the referral or perform the scan. The Telomyx website lists current service and location information, but neither a webpage nor a booking request guarantees an exposure.
Medical bone-health concerns, fragility fractures and possible osteoporosis require the appropriate clinician-led assessment. Do not use a body-composition result to start, stop or change prescription treatment.
Consistency makes trends more useful
When a clinician recommends a follow-up scan, comparability matters:
- use the same facility and machine where practicable;
- follow the same provider’s preparation instructions;
- keep earlier reports, including the measured sites and machine details;
- tell the team about new fractures, medicines, surgery or health conditions;
- interpret change against the facility’s measurement precision, not just the raw difference.
The practical message is simple. Read the appointment letter, keep prescribed medicines unchanged unless specifically instructed, wear metal-free clothing when possible, disclose recent contrast or nuclear medicine, and report possible pregnancy before travelling. If the local instructions differ from a general article, the local scanning team should resolve the difference.
The content in this article is for educational purposes only and does not constitute medical or dietary advice. If you have an underlying health condition, are taking medication, or are considering significant changes to your diet or exercise regimen, consult a qualified healthcare professional before making any adjustments.
