What should you know about a BMI DEXA scan?

BMI compares weight with height, but it cannot distinguish muscle, fat and bone. DEXA imaging gives a more detailed picture of bone mineral density and, when requested, the distribution of lean tissue and fat. The result is interpreted with your age, sex, medical history and reason for testing rather than viewed in isolation.

A clinician may request bone assessment when there are concerns about fragile bones, long-term steroid treatment, or hormonal changes such as premature ovarian insufficiency. The scan itself does not diagnose every cause of low bone density.

Tell the imaging team if you may be pregnant, have recently had a contrast examination, or cannot lie flat. Wear comfortable clothing without metal fasteners if possible and follow the centre's instructions about medicines and food. During the scan, you lie still while the scanner passes over the selected areas; the process is usually brief and does not involve an injection.

Bring details of fractures, medical conditions and medicines so the report can be interpreted properly. Ask whether the appointment is measuring bone density, body composition, or both.

Contact the clinician who arranged the scan if you have new severe bone pain, a fall followed by difficulty using a limb, or a suspected fracture. Seek urgent help for sudden severe pain with loss of movement or a new neurological symptom. A scan result that suggests reduced bone density needs a planned review to discuss fracture risk and next steps.

Which part of the scan is relevant to my health goal? How should my BMI be interpreted alongside the DEXA findings? Do I need a repeat Bone Density Scan, and what changes to exercise, nutrition or medicines would be appropriate?