Bone Density Scan
Reviewed
A bone density scan uses a low-dose x-ray to measure calcium and other minerals in bones. It helps diagnose osteopenia and osteoporosis, predict fracture risk, and monitor treatment. The most common method is a central DEXA scan, which checks the lower spine, hip, wrist, or entire body.
Preparation and collection
You may be told to stop taking calcium supplements 24 to 48 hours before the test. Avoid wearing metal jewelry or clothes with metal parts such as buttons or buckles.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- The test uses low-dose radiation; it is not recommended during pregnancy.
- Central DEXA scans may be less accurate if you have a history of spinal surgery, spinal deformity, fractures, or arthritis in your spine.
- Peripheral DEXA (p-DEXA) scans provide good information about fracture risk but cannot give as much detail as a central DEXA scan.
- Results labeled as osteopenia or osteoporosis are based on statistical comparisons and may not fully capture individual fracture risk; clinical follow-up is necessary.
- The test does not measure bone quality or other factors affecting bone strength.
What to do next
If your results show low bone density (osteopenia) or osteoporosis, your provider will recommend steps to prevent further bone loss: getting more exercise (walking, dancing, weight machines), adding calcium and vitamin D to your diet, and possibly taking prescription medicines. Your provider may suggest repeat scans based on your fracture risk: every 2 years for high risk, every 3-5 years for moderate risk, and every 10-15 years for low risk. Additional tests (calcium blood test, vitamin D test, hormone tests) may be ordered to confirm a diagnosis or monitor treatment.