Bone Density Test (DEXA Scan): When to Get One and What the Results Mean

A complete guide to bone density screening: who needs it, when to get tested, and how to understand your results.

Concerns about bone health as we get older are real. Hormonal changes, loss of muscle mass[muh-suhl mas]nounThe total weight of muscle in your body, critical for longevity.Learn MoreClose, and other age-related factors disrupt bone remodeling, when old, brittle bone is broken down and removed and replaced with new bone.

The result? As we age, more bone is removed than added, leading to lower bone mass and higher risk of fracture. Nearly 1 in 5 women and 1 in 20 men over the age of 50 are affected by osteoporosis.

While we can’t restore the peak bone mass we had in our 30s, interventions like weight-bearing exercise (including HIIT workouts), sound nutrition, and, in some cases, medication can help slow bone loss and help maintain bone strength. Knowing your baseline, the status of your bones right now, may be a good first step.

What is a DEXA Scan?

Bone mineral density[bohn min-er-uhl den-si-tee]nounA key indicator of bone strength and fracture risk.Learn MoreClose (BMD), the amount of calcium and other minerals in bone that contributes to its strength, is measured using dual energy X-ray absorptiometry (DEXA or DXA) scan.

The low-radiation test compares your BMD to a young adult of the same sex, generating a T-score that reflects how far above or below your bone density is from that average. A score of 0, for example, means your bone is healthy; scores below 0 (-1 or lower) indicate weaker bone. 

Research shows fracture risk increases by 1.5 to 2 times with each 1-point drop in T-score. 

T-score Key

• -1 or above = normal bone density

• -1 to – 2.5 = low bone mass (formally called osteopenia)

• -2.5 or below  = osteoporosis

When to Get a Bone Density Test

DEXA is currently recommended for women at age 65 or older, and for men age 70 or older. It’s sometimes given to women 50 and older with risk factors, including:

• Prior fracture
• Long-term steroid use
• Parent with hip fracture
• Lower body weight
• Current cigarette smoker
• Heavy alcohol use
• Rheumatoid arthritis 
• Celiac disease
• Low testosterone (men)
• Overactive thyroid or parathyroid disease 
• Early menopause

But there is growing interest in offering DEXA scans sooner, and particularly to post-menopausal women as young as 50. 

“I used to think ‘no,’ but now I do think it’s wise to get it done earlier, because then we can start on prevention,” says Heather Hofflich, DO, an endocrinologist and professor of clinical medicine at University of California San Diego Health. 

If a DEXA scan indicates lower bone mass before age 65, “it’s good to know,” Hofflich says.  That’s because aging itself is a risk factor for fracture. This is when preventive care becomes even more important, and may include supplemental calcium or vitamin D[vai-tuh-min dee]nounA vitamin essential for bone health and immune function.Learn MoreClose, or, in some cases, medication.

A landmark study published early this year found that early-postmenopausal women over 50 with below-average bone density who received two doses of a medication called zoledronate, reduced their risk of vertebral fracture by 44% over the next decade. This nonhormonal medication offers a possible alternative to hormone therapy (HT). While prescribed to help reduce menopausal symptoms, HT can also help protect bone. It’s not recommended solely for osteoporosis prevention, however, because of potential health risks, including blood clots, stroke, and some cancers.

How to Get a Bone Density Test and What it Costs

Medicare covers osteoporosis screening for women 65 and older, or for younger women or men with qualifying risk factors. Private insurance coverage varies, so you’ll need to check coverage with your provider. 

If paying out of pocket, bone density tests typically cost $150-300. Some health spas and fitness centers now offer DEXA scans to measure body fat and lean muscle mass, and may provide T-scores as part of the report. Just make sure to take the results to your primary care doctor, Hofflich says. They can help you analyze the information and, if needed, a prevention plan. Also, if you’re on, or considering, GLP-1 drug therapy, you may want to get a baseline DEXA scan in order to track your muscle mass, according to Dr. Eric Topol, founder and director of the Scripps Research Translational Institute.

Two Other Bone Health Tests to Consider: FRAX and Trabecular Bone Score

1) FRAX score: The free online FRAX calculator estimates your 10-year probability of hip fracture or major osteoporosis-related fracture, based on age, sex, and basic risk factors. “It’s far from perfect, but most medical organizations recommend it as a tool for those who are curious about their bone health,” says Donald Miller, PharmD, professor emeritus at North Dakota State University.  The FRAX assessment can be used on your own with or without DEXA results, though is often recommended when low-bone mass is indicated. Find the FRAX calculator here. 

2) Trabecular bone score: Sometimes offered alongside DEXA scan, this software analysis provides information about bone microarchitecture. It’s particularly helpful to medical experts when T-scores are misleading, such as with osteoarthritis, which can falsely elevate bone density, Hofflich explains. “That’s where the trabecular bone score helps us; it looks a little deeper and can tell me, in that bone microarchitecture, [the bone quality] is not as good as it looks.” 

Protecting Bone Health at Any Age

DEXA is still the gold standard for determining bone health, Hofflich says. And if you’re a woman age 65 or older, or a man 70 or older, Medicare and most insurers will cover it. 

If you’re younger and don’t have risk factors, you can ask whether or not your insurer will pay. Or, you can opt to pay for the test yourself.

You can also take a free online FRAX assessment to gauge your fracture risk over the next 10 years.

Meanwhile, the best strategies for protecting bone as we age are the same for everyone: weight-bearing exercise, a balanced diet rich in calcium, maintaining healthy vitamin D levels, and avoiding habits that accelerate bone loss. “That’s all we know,” says Hofflich. 

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