Axial DEXA scan: what to expect and what the results mean

An axial DEXA scan uses low-dose X-rays to measure bone density, usually at the hip and lower spine. It helps a clinician assess bone strength, identify reduced bone density and decide whether monitoring or treatment is appropriate. The scan does not show bone quality in every detail, so the result is considered alongside your age, medical history, medicines and fracture history.

A report may include a T-score, which compares your measurement with that of a healthy young adult, and a Z-score, which compares it with people of a similar age and sex. Which score matters most depends on your age and clinical situation. A single value does not determine your whole fracture risk; your clinician also considers previous fractures, family history, menopause or hormone changes, smoking, long-term steroid use and other health conditions.

Follow-up scans are most useful when they can be compared reliably. Different machines, positioning or scan centres can affect comparison, so bring earlier reports if available.

Wear loose clothing without metal around the waist or hips, and be ready to remove belts, coins or jewellery that could interfere with the image. Tell the imaging team if you may be pregnant, recently had a contrast examination, or take calcium supplements; they can advise whether the timing or preparation needs to change. During the scan, you lie still on a padded table while the scanner passes over the measured area. No injection is usually needed for a standard axial DEXA scan.

The scan itself is not an emergency test. Seek prompt medical assessment for sudden severe back, hip or groin pain after a minor fall or ordinary movement, especially if you cannot stand or bear weight. Go to urgent care immediately if back pain comes with new leg weakness, numbness around the groin, or loss of bladder or bowel control. These symptoms need direct assessment rather than waiting for a scheduled bone-density appointment.

Ask which skeletal sites were measured, whether the T-score or Z-score is more relevant for you, and whether any arthritis, previous surgery or positioning issue affected the reading. You can also ask how the finding changes your care, whether blood tests are needed to look for a cause of bone loss, and when comparison imaging would be informative.