Medically reviewed by Dr. Numair Younis, M.B.B.S. (K.E.M.U.), FEBNM European Fellowship in Nuclear Medicine, Consultant Nuclear Medicine Physician, Al-Nasar Lab & Diagnostic Centre. Updated August 2026.
Quick answer: A DEXA scan measures how dense your bones are, usually at the hip and spine, to detect osteoporosis before a fracture happens. The result is a T score. Above minus 1.0 is normal, between minus 1.0 and minus 2.5 is osteopenia, and minus 2.5 or lower is osteoporosis. The scan is painless, takes about 15 minutes and uses very little radiation.
Book a DEXA scan: call 0300 0341944 or request an appointment.
What is a DEXA scan?
DEXA stands for Dual Energy X-ray Absorptiometry. The scanner passes two very low dose X-ray beams of different energies through the bone. Because bone and soft tissue absorb the two beams differently, the machine can calculate exactly how much mineral is packed into the bone and therefore how strong it is.
It is the internationally accepted standard for diagnosing osteoporosis, and it does something an ordinary X-ray cannot. A plain X-ray only shows thinning bone once roughly a third of the mineral has already been lost. DEXA detects the problem long before that point.
What does your T score mean?
The T score compares your bone density against that of a healthy young adult at peak bone mass. It is expressed as a number of standard deviations above or below that reference.
| T score | What it means | What usually follows |
|---|---|---|
| Above minus 1.0 | Normal bone density | Routine monitoring based on your risk factors |
| Minus 1.0 to minus 2.5 | Osteopenia, meaning lower than normal but not osteoporosis | Calcium, vitamin D, weight bearing exercise, repeat scan |
| Minus 2.5 or lower | Osteoporosis | Treatment to reduce fracture risk, plus monitoring |
You may also see a Z score on your report. This compares you against people of your own age and sex rather than a young adult, and it is the more meaningful figure for premenopausal women, men under 50 and children.
Who should have a bone density scan?
- Women aged 65 and above, and men aged 70 and above
- Postmenopausal women under 65 with additional risk factors
- Anyone who has broken a bone from a minor fall or knock after the age of 50
- People taking long term steroid medication
- Women who went through early menopause or had their ovaries removed
- People with rheumatoid arthritis, thyroid or parathyroid disorders, or conditions affecting nutrient absorption such as coeliac disease
- Anyone with a family history of hip fracture, or who has lost noticeable height
- People with long standing vitamin D deficiency
That last point deserves emphasis in Pakistan, where vitamin D deficiency is extremely common even in a sunny climate. Vitamin D is what allows the body to absorb calcium, so a prolonged deficiency directly undermines bone strength. If you have been diagnosed with low vitamin D, discuss bone density with your doctor. Our vitamin D test page explains that side of the picture.
Why does osteoporosis matter before a fracture?
Osteoporosis has no symptoms. There is no ache that warns you, no stiffness that builds. For most people the first sign is a broken bone, often a wrist, spine or hip, from a fall that would not have harmed them years earlier.
A hip fracture in an older adult is a serious event with lasting consequences for independence and mobility. The purpose of a DEXA scan is to intervene while there is still time, because bone loss can be slowed and in many cases partly reversed once it is identified.
How do you prepare for a DEXA scan?
- Avoid calcium supplements for about 24 hours before the scan, since undigested tablets can affect the reading
- Wear comfortable clothing without metal. Zips, buckles and underwired garments interfere with the images
- Tell the team if you have had a barium study, CT contrast or nuclear medicine scan in the past week, as these can distort the result
- Tell staff if you are, or might be, pregnant
- Bring any previous DEXA reports, since the trend over time is often more useful than a single reading
What happens during the scan and is it safe?
You lie fully clothed on a padded table while a scanning arm passes above you. Nothing touches you, nothing is injected, and there is no enclosed tunnel, so the scan is comfortable even for people who find MRI difficult. It usually takes 10 to 20 minutes.
The radiation dose is very low, considerably less than a standard chest X-ray and comparable to the natural background radiation you receive in a normal day. For the great majority of patients, the information gained far outweighs that minimal exposure.
DEXA scanning at Al-Nasar Lab
Al-Nasar Lab & Diagnostic Centre provides DEXA bone density scanning at its main Johar Town campus, alongside X-ray, CT, MRI, ultrasound and nuclear medicine. Scans are reported by qualified consultant radiologists, and related tests such as vitamin D, calcium and thyroid function can be arranged at the same visit, which is often exactly what a doctor wants alongside a bone density result.
Explore our imaging services, find your nearest branch, or call 0300 0341944 to book.
Frequently Asked Questions
Is a DEXA scan painful?
No. You simply lie still on a table while the scanning arm passes over you. Nothing touches or enters the body.
How much radiation does a DEXA scan use?
Very little, considerably less than a standard chest X-ray and similar to the natural background radiation of an ordinary day.
How often should a DEXA scan be repeated?
Usually every one to two years if you are being monitored or treated. Your doctor sets the interval based on your result and your risk factors.
What is the difference between a DEXA scan and a bone scan?
They are completely different. A DEXA scan measures bone density to assess fracture risk. A nuclear medicine bone scan uses a tracer to find areas of active bone disease such as infection, fracture or cancer spread.
Can osteoporosis be reversed?
Bone loss can be slowed and often partly improved with treatment, adequate calcium and vitamin D, and weight bearing exercise. Results are far better when the condition is found before a fracture occurs.
This article is for general information and is not a substitute for medical advice. Please discuss your scan and results with a qualified doctor.
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