Bone mineral density testing is used to find osteoporosis, a disease in which the bone’s mineral content and density are low, increasing the risk of breaking a bone. The test, also known as bone densitometry, quickly and accurately measures the amount of calcium in certain parts of your bone. From this information your doctor can determine how strong your bones are. (We use the DXA method, which stands for dual-energy X-ray absorptiometry.)

How Do I Prepare for a Bone Mineral Density Test?

You don’t have to change your daily routine before this test. Eat, drink and take your medicines as you normally would.

That said, you’ll need to avoid:

  • Any tests with barium or IV contrast two weeks prior to the bone density test
  • Calcium supplements (such as Tums) for 24 hours before the test
  • Clothing with metal zippers or buttons
  • Jewelry or body piercings.

What Can I Expect During the Test?

You might be asked to wear a hospital gown if your clothing contains any metal. You’ll need to lie still on a padded table while a movable arm passes over the area of your body being measured, usually the lower back, hip, forearm or knee. The test will take about 30 minutes.

What Are the Risks and Benefits of the Method We Use?

DXA uses a low level of radiation (about the same as you would get on a flight from New York to Los Angeles), but detects low levels of bone loss much better than a simple X-ray can.

Please inform the technologist if you are pregnant.

Who Should Have a Bone Density Test?

The test is given to those at highest risk of developing osteoporosis, or to check the effectiveness of treatment for osteoporosis. However, because osteoporosis is such a common disorder, it may be done for other reasons.

When Should a Bone Density Test Be Repeated?

This depends on why it is being recommended — whether as a follow-up to the results of previous testing, to monitor therapy, as a screening tool, or for some other reason.

Coverage by insurance and health systems will vary.

In some situations, such as starting high-dose steroids like prednisone or prednisolone, a test may be done as often as every six months. After starting a medication for osteoporosis, it may take one or two years or longer before a significant change in bone density occurs.

This information is for educational purposes only. It is not intended to replace the advice of your health care providers. If you have any questions, talk with your doctor or others on your health care team.