As you get older, your bones can become thinner and weaker. That means you could be at a higher risk of developing osteoporosis or even fracturing a bone.
A simple, painless scan called a dual-energy x-ray absorptiometry (DEXA) scan can measure the density of your bones to help evaluate their strength. “DEXA scans use low-dose x-rays to look at your bones. Essentially, they measure the amount of calcium in your bones and compare it to others of your same sex, age and ethnicity,” said Jill Jones, a radiologic technologist at Banner Health in Arizona.
Here’s who should have a DEXA scan
If you’re a woman over age 65 or a man over age 70, your health care provider will probably recommend a DEXA scan. Why the different age recommendations? Women are more prone to osteoporosis than men—about 80% of people in the U.S. with osteoporosis are women, and almost one in five women over age 50 has osteoporosis in their upper leg or spine, according to the Centers for Disease Control (CDC). You may also need a DEXA scan if you’re younger but at higher risk for bone loss.
Here’s what it’s like to have a DEXA scan
“This procedure is a painless procedure and takes just 10 to 15 minutes,” Jones said. “The only thing you need to do to prepare is to stop taking calcium or vitamin D supplements for 24 hours before the exam since they can show up on the scan.” You can wear your own clothing if it doesn’t have any metal in the area that’s being scanned.
You will lie on a table and get a low-dose x-ray in two to three areas, usually the lower back, hip and forearm. “People often ask why we look at the low back and hip areas. It’s because the large weight-bearing bones in the body give us an accurate measurement of the mineralization of the bones. If we see osteoporosis in these bones, the likelihood of osteoporosis in the smaller bones is high,” Jones said.
The DEXA scan x-ray dose is very low—just enough for the scan to show the mineralization of the bones. It can’t show fractures, arthritis or other bone diseases.
Here’s what the results can tell you
If your results are normal, you’ll probably have follow-up screenings every two to three years to make sure nothing has changed with your bones. If your results show signs of osteoporosis, your health care provider may recommend prescription medications that can help slow your bone loss. Your health care provider may also suggest other steps you can take to help lessen the effects of osteoporosis, such as weight-bearing exercise, multivitamins, calcium and vitamin D.
The bottom line
As you age, it’s common to lose strength in your bones. Starting at age 65 for women or 70 for men at average risk, a DEXA scan can help watch for signs that your bones are weakening. If signs are found, you can take steps to keep them as strong as possible.
Learn more about how aging can affect your bones and how you can fight back: