Should I have a dual-energy X-ray absorptiometry (DEXA) test to diagnose osteoporosis?
Introduction
This information will help you understand your choices, whether you share in the decision-making process or rely on your doctor's recommendation.
Key points
A bone density test, called DEXA or dual-energy X-ray absorption, measures bone mass to determine whether you have osteopenia or osteoporosis and are at risk for a fracture. (Other bone density tests are available but are less accurate.) Consider the following when making your decision:
- It is important to know whether you are at risk for osteoporosis. It is possible to assess your risk for developing osteoporosis without bone density testing. Click here to assess your risk.
- Not everyone needs testing. Testing is probably not appropriate at this time if you:
- Are at low risk for osteoporosis and are younger than 65.
- Have osteoporosis but are not ready to make lifestyle changes or take medications to treat it.
- The Osteoporosis Society of Canada recommends that people 65 years and older have a bone mineral density (BMD) test to screen for osteoporosis.1 If you are at increased risk for osteoporotic fractures, screening should begin earlier. Ask your doctor about your risk factors and whether you should be tested for osteoporosis before age 65.
- Bone density testing is appropriate if you are at risk of osteoporosis and are willing to make lifestyle changes and seek treatment for osteoporosis.
Medical Information
What is osteoporosis?
Osteoporosis causes bones to become thin and brittle, making them more likely to break. Bones naturally become thinner as you grow older. Old bone dissolves and is absorbed into the body faster than new bone is made. As this occurs, the bones lose minerals (such as calcium), heaviness (mass), and structure, making them weaker. The thicker your bones are, the longer it takes to develop osteoporosis.
What is the DEXA bone density test?
The DEXA bone density test measures bone thickness. This test can help predict your chances of having a broken bone due to osteoporosis. There are no known risks associated with having the DEXA bone density test.
The decision to test your bone thickness is based on your risks for osteoporosis, such as your age and family history, being a post-menopausal woman, or smoking. The outcome of the bone density test may indicate that you need treatment for osteoporosis.
What are the risk factors for osteoporosis?
The main risk factor for osteoporosis is being a woman who has gone through menopause. However, not all post-menopausal women are at risk. Many factors that influence your risk cannot be changed, such as family history. Other risks can be modified, such as stopping smoking. If you can reduce your risk for osteoporosis, you may not need to take the bone density test at this time. Review the following lists to see if you can reduce your risk for osteoporosis.
- Risk factors you cannot change include:
- Being a woman who has gone through menopause. Women who went through early menopause (before age 45) and did not take hormone therapy have the greatest risk.
- Having a family history (mother, father, or sibling) of osteoporosis. It is possible your relative may not have been diagnosed. A relative who had unexplained or easily broken bones may have had undiagnosed osteoporosis.
- Being of European or Asian ancestry.
- Having a medical condition such as hyperthyroidism or another condition that makes the body unable to absorb enough calcium.
- Having surgery to remove your ovaries before menopause.
- Having a small frame. People with small frames are more likely to develop osteoporosis, because they have smaller bones and less bone mass.
- Risk factors you can modify include:
- Lifestyle and environmental factors such as:
- Smoking.
- Excessive use of alcohol.
- Getting little or no weight-bearing exercise.
- A diet low in foods containing calcium, phosphorus, and vitamin D.
- Using corticosteroids for 6 months or longer (but you may not be able to stop taking corticosteroids depending on why you are taking them).
Who should get a bone density test?
The Osteoporosis Society of Canada recommends that people 65 years and older have a bone mineral density (BMD) test to screen for osteoporosis.1 If you are at increased risk for osteoporotic fractures, screening should begin earlier. Ask your doctor about your risk factors and whether you should be tested for osteoporosis before age 65.
If you are younger than 60 and have one or more risk factors for osteoporosis, you may want to consider whether a bone density test is right for you. It is possible to reduce your risk for broken bones and other effects of osteoporosis with treatment and lifestyle changes.
If you have a low trauma fracture, you may want to have a bone density test. Low trauma means that you broke a bone doing something that would not normally cause a broken bone. This includes normal daily activities or a simple fall.
If you are diagnosed with osteoporosis and start treatment, you may want to have follow-up bone mineral density tests to see how well the treatment is working. You usually get these follow-up tests no more often than every 2 years.2 But getting follow-up tests does not make your treatment work better.3
What to expect if you DO get a bone density test
If you have risk factors for osteoporosis and choose to get the bone density test, the results may indicate whether you need treatment. Treatment can help strengthen bones and prevent fractures.
What to expect if you do NOT get a bone density test
A bone density test is not generally useful if you are under age 65 and do not have risk factors for osteoporosis. But if you are very concerned or afraid about getting osteoporosis, talk to your health professional about lifestyle changes you can make to keep your bones strong.
If you do not have risk factors for osteoporosis and are living a lifestyle that is consistent with maintaining strong bones (doing weight-bearing exercises, getting enough calcium and vitamin D, and not smoking), the bone density test is not recommended until age 65.
If you do have risk factors but you are living a healthy lifestyle and getting enough calcium and vitamin D and are not willing to take medications, the bone density test may be unnecessary as it would not change what you are doing now to maintain strong bones.
For more information, see the topic Osteoporosis.
Your Information
Your choices are:
- Have the test and get the information to make your decision about treatment, if necessary.
- Don't have the test and continue to make lifestyle changes to reduce your risk of fractures.
The decision about whether to have this test takes into account your risk factors for osteoporosis, your personal feelings, and the medical facts. It's important that you know whether you are at risk for osteoporosis. Click here to assess your risk.
Deciding whether to have osteoporosis testing Reasons to have the test Reasons not to have the test
- You are a woman age 65 or older or have other risk factors for osteoporosis.
- You are willing to make changes and try treatment to reduce your risk for fractures if you have osteoporosis.
- Testing is accurate, painless, and quick.
- The test is safe. Radiation exposure is minimal.
Are there other reasons you might want to have the test?
- You are at low risk for osteoporosis.
- You will not seek treatment even if you have osteoporosis.
- You have osteoporosis but are already receiving treatment to reduce your risk of fractures.
- This test is not available in your area.
- It can give false-positive results.
Are there other reasons you might not want to have the test?
These personal stories may help you make your decision.
Wise Health Decision
Worksheet
Use this worksheet to help you make your decision. After completing it, you should have a better idea of how you feel about having this test. Discuss the worksheet with your health professional.
Circle the answer that best applies to you.
I am worried I might develop osteoporosis. Yes No Unsure I have some risk factors for osteoporosis. Yes No Unsure I would be willing to take medications to prevent or treat osteoporosis if needed. Yes No Unsure Finding out I have osteoporosis will help me decide to seek treatment options. Yes No Unsure I am willing to make any needed lifestyle modifications (such as starting a weight-bearing exercise program or changing my diet) if I find out I have osteoporosis. Yes No Unsure I am already reducing my risk through exercise, adequate calcium and vitamin D, and not smoking. Yes No Unsure Use the following space to list any other important concerns you have about this decision.
What is your overall impression?
Your answers in the above worksheet are meant to give you a general idea of where you stand on this decision. However, you may have one overriding reason to have or not to have bone density testing.
Check the box below that represents your overall impression about your decision.
Leaning toward having the test
Leaning toward NOT having the test
Return to the topic:
| Author: | Douglas Dana Robin Parks, MS | Last Updated: February 21, 2007 |
| Medical Review: | Joy Melnikow, MD, MPH - Family Medicine Carla J. Herman, MD, MPH - Internal Medicine Andrew Swan, MD, CCFP, FCFP - Family Medicine | |
 | ||
| |