LAB TEST
Bone mineral density test
A bone mineral density (BMD) test measures how much calcium and other types of minerals are in an area of your bone. This test helps your health care provider detect osteoporosis or bone loss and predict your risk for bone fractures.
How the Test is Performed
Bone density testing can be done in several ways. The most common and accurate way uses a dual-energy x-ray absorptiometry (DEXA) scan. DEXA uses low-dose x-rays . (You receive more radiation from a chest x-ray.) There are two types of DEXA scans: Central DEXA -- You lie on a soft table. The scanner passes over your…
How to Prepare for the Test
If you are or could be pregnant, tell your provider before this test is done. DO NOT take calcium supplements for 24 hours before the test. You'll be told to remove all metal items from your body, such as jewelry and buckles.
How the Test will Feel
The scan is painless. You need to remain still during the test.
Why the Test is Performed
Bone mineral density (BMD) tests are used to: Diagnose bone loss and osteoporosis See how well osteoporosis medicine is working Predict your risk for future bone fractures The US Preventive Services Task Force recommends this test for women age 65 and older and for some women younger than age 65 who have an increased…
Normal Results
The results of your test are usually reported as a T-score and Z-score: T-score compares your bone density with that of a healthy young woman. Z-score compares your bone density with that of other people of your age, sex, and race. With either score, a negative number means you have thinner bones than the comparison…
What Abnormal Results Mean
Bone mineral density testing does not diagnose fractures. Along with other risk factors you may have, it helps predict your risk for having a bone fracture in the future. Your provider will help you understand the results. If your T-score is: From -1 to -2.5, you may have bone loss (osteopenia) Below -2.5, you likely…
Risks
Bone mineral density uses a slight amount of radiation. Most experts feel that the risk is very low compared with the benefits of finding osteoporosis before you break a bone.
References
Almohaya M, Almehthel M, Kendler D. Dual x-ray absorptiometry and measurement of bone. In: Hochberg MC, Gravallese EM, Smolen JS, van der Heiide D, Weinblatt ME, Weisman MH, eds. Rheumatology . 8th ed. Philadelphia, PA: Elsevier; 2023:chap 48. LeBoff MS, Greenspan SL, Insogna KL, et al. The clinician's guide to…
This is a summary. Read the full article at www.ucsfbenioffchildrens.org (reviewed 01/04/2023).
This page is general information and is not medical advice. It does not replace a registered doctor, and it is not a prescription or a recommendation to use any medicine or test. Prices are listed prices and may change. Always follow the advice of your doctor or pharmacist.