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Osteoporosis Health Center

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Bone Mineral Density

What Affects the Test

Reasons you may not be able to have the bone mineral density (BMD) test or why the results may not be helpful include:

  • Inability to be correctly positioned during the test.
  • Having a broken bone in the past. This can cause falsely high BMD results.
  • Arthritis of your spine. In this case, the changes caused by arthritis in the spine may not make the spine the best place to measure for osteoporosis.
  • Metal implants from hip replacement surgery or hip fracture.
  • Having an X-ray test that uses barium within 10 days of the BMD test.

What To Think About

  • Experts disagree about which bones are best to use for BMD measurements. Bones in the lower spine camera.gif and hip camera.gif are tested most often. These bones generally have the most bone loss and are more likely to fracture. Sometimes bones in the wrist are measured. Ultrasound screening is done on the bone in the heel.
  • A BMD measurement should be done only when the information provided by the test will affect treatment decisions. BMD does not need to be measured more often than every 2 years to find out how well treatment is working.
  • Using DEXA to measure bone mineral density is replacing older methods, such as dual photon absorptiometry (DPA).
  • Regular X-rays cannot detect mild bone loss. A bone must lose at least a quarter of its weight before a regular X-ray can detect the problem.
  • If your bone density is lower than normal, you can increase bone density and strength by exercising, lifting weights or using weight machines, getting enough calcium and vitamin D, and taking some medicines. To learn more about how you can increase your bone strength and density, see the topic Osteoporosis.

Citations

  1. U.S. Preventive Services Task Force (2011). Screening for Osteoporosis: Recommendation Statement. Available online: http://www.uspreventiveservicestaskforce.org/uspstf10/osteoporosis/osteors.htm.

  2. Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.

Other Works Consulted

  • Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.

  • Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.

  • Liu H, et al. (2008). Screening for osteoporosis in men: A systematic review for an American College of Physicians guideline. Annals of Internal Medicine, 148(9): 685–701.

  • Nayak, S, et al. (2006). Meta-analysis: Accuracy of quantitative ultrasound for identifying patients with osteoporosis. Annals of Internal Medicine, 144 (11): 832–841.

  • Qaseem A, et al. (2008). Screening for osteoporosis in men: A clinical practice guideline from the American College of Physicians. Annals of Internal Medicine, 148(9): 680–684. Also available online: http://www.acponline.org/clinical_information/guidelines/guidelines.

  • U.S. Preventive Services Task Force (2011). Screening for Osteoporosis: Recommendation Statement. Available online: http://www.uspreventiveservicestaskforce.org/uspstf10/osteoporosis/osteors.htm.

WebMD Medical Reference from Healthwise

Last Updated: August 30, 2012
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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