How does bone density scan work?

A DEXA scanner sends two X-ray energies through the body. The difference in how bone and soft tissue absorb them helps calculate mineral density. You remain dressed if clothing does not contain metal, lie on a padded table and keep still while the scanner passes over the selected areas. The scan is brief and does not involve an injection. A report compares the measurement with reference values and helps a clinician assess fracture risk or possible osteoporosis. The result is interpreted alongside age, medical history, medicines and previous fractures.

Tell the imaging team if you may be pregnant, recently had a contrast examination, or take calcium supplements. Wear clothing without metal where possible and follow the centre’s instructions about supplements or eating. Bring previous bone reports if available, because changes over time can be more useful than one isolated result. Keep the appointment still and tell the operator if a position is uncomfortable.

The scan itself is not an emergency test. Seek prompt care after a fall if you have severe pain, cannot bear weight, or notice a new deformity, because these may indicate a fracture. Arrange a clinical review if you have repeated fractures, height loss or long-term medicine use that may weaken bone; a clinician can decide whether scanning is appropriate.

Ask which body sites will be scanned, how your result relates to fracture risk, whether another condition affects interpretation, and when a repeat assessment might be useful.