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Bone mineral density testing: Do you need it?

Bone mineral density (BMD) test, also called densitometry or a DEXA scan, is a tool doctors use to assess your bone health. This painless test uses X-rays to measure the amount of calcium and minerals in a segment of bone. The higher your bone mineral content, the stronger your bones are. The test can determine whether you’re at risk for or already have osteoporosis, a disease that causes bones to become fragile and more likely to break. The test can also monitor your response to osteoporosis treatments.

Who should get the test

The National Osteoporosis Foundation recommends bone density testing for:

  • women age 65 or older
  • postmenopausal women younger than age 65 with one or more risk factors for osteoporosis (having a family history of osteoporosis, being thin or having chronic health problems such as diabetes or hypothyroidism)
  • those who’ve fractured a bone and are older than age 50
  • postmenopausal women who’ve stopped taking hormone therapy

What to expect

The most common test uses scanners with low-dose X-rays. The scanner passes over your body and takes X-rays of your wrist, forearm, heel, lower spine or hip.

What the results mean

After the test, you’ll get two scores. The T-score compares your bone density with that of healthy young women. The Z-score compares your bone density with that of other people of your age, gender, weight and ethnicity. In either score, a negative number means you have thinner bones than the standard. The greater the negative the number, the thinner your bones.

Talk to your healthcare provider about your results. He or she can discuss possible treatment options that may be available to you.