If you’re wondering when to get a bone density test, here’s the straightforward answer: women should start screening at age 65, and men at age 70. But if you have risk factors — early menopause, long-term steroid use, a fragility fracture after 50, or a family history of osteoporosis — you may need screening much earlier, sometimes in your 50s or even your 40s.
A bone density test (technically called a DEXA scan, short for dual-energy X-ray absorptiometry) takes about 10–15 minutes, uses less radiation than a standard chest X-ray, and gives you a number called a T-score that tells you exactly where your bones stand. It’s the single most reliable way to catch osteoporosis before a fracture happens — and considering that 1 in 2 women and 1 in 4 men over 50 will break a bone due to osteoporosis, that early heads-up matters enormously.
Who Needs a Bone Density Test? Screening Guidelines by Age and Sex
The U.S. Preventive Services Task Force (USPSTF) and the National Osteoporosis Foundation both publish screening recommendations. Here’s how they break down:
| Group | When to Screen | Guideline Source |
|---|---|---|
| Women aged 65+ | Routine screening recommended | USPSTF (Grade B) |
| Postmenopausal women under 65 with risk factors | Screen based on risk assessment (e.g., FRAX tool) | USPSTF (Grade B) |
| Men aged 70+ | Routine screening recommended | NOF / Endocrine Society |
| Men aged 50–69 with risk factors | Screen based on clinical judgment | NOF / Endocrine Society |
| Adults with fragility fracture after age 50 | Screen regardless of age or sex | USPSTF, NOF, AACE |
| Adults on glucocorticoids ≥3 months | Screen at initiation of therapy | ACR Guidelines |
| Adults with conditions causing bone loss (hyperparathyroidism, celiac disease, etc.) | Screen based on clinical judgment | Endocrine Society |
One thing that catches many patients off guard: the USPSTF currently states there is insufficient evidence to recommend routine screening in men under 70 without risk factors. That doesn’t mean men shouldn’t be screened — it means the data gaps haven’t been filled yet. If you’re a man in your 50s or 60s with risk factors, push for the test.
Risk Factors That May Move Your Screening Age Earlier
Age and sex aren’t the whole picture. The following risk factors can shift the screening window significantly earlier:
- Early menopause (before age 45) or surgical menopause (oophorectomy)
- Low body weight — BMI under 20 is a strong independent risk factor
- Parental hip fracture — doubles your own hip fracture risk
- Smoking (current) and excessive alcohol (≥3 drinks/day)
- Long-term corticosteroid use — prednisone ≥5 mg/day for 3+ months
- Rheumatoid arthritis, celiac disease, type 1 diabetes, hyperthyroidism
- Androgen deprivation therapy in men with prostate cancer
- Aromatase inhibitor therapy in women with breast cancer
Your doctor can plug your specific risk factors into the FRAX calculator (developed by the WHO), which estimates your 10-year probability of a major osteoporotic fracture. A 10-year major fracture risk ≥9.3% in postmenopausal women under 65 generally triggers a screening recommendation.
How T-Scores Work: What Your DEXA Results Actually Mean
Your DEXA scan produces a T-score that compares your bone mineral density to the peak bone density of a healthy 30-year-old of the same sex. Here’s what the numbers mean:
| T-Score Range | Classification | What It Means |
|---|---|---|
| −1.0 and above | Normal | Bone density is within the expected range |
| −1.1 to −2.4 | Osteopenia (low bone mass) | Below normal but not yet osteoporosis; increased fracture risk |
| −2.5 and below | Osteoporosis | Significantly reduced bone density; high fracture risk |
| −2.5 and below + fragility fracture | Severe osteoporosis | Treatment is strongly indicated |
Each full point decrease in T-score roughly doubles your fracture risk. So a T-score of −3.0 carries substantially more risk than −2.0, even though both sound similar on paper.
You’ll also see a Z-score on your report, which compares you to people of your own age and sex rather than a 30-year-old. Z-scores below −2.0 suggest something beyond normal aging is driving bone loss — such as a secondary cause that warrants further workup.
What to Expect During the DEXA Scan
The actual test is anticlimactic in the best way. You lie fully clothed on a padded table (no gown needed unless you have metal zippers or buttons). A low-dose X-ray arm passes over your lumbar spine and hip — the two sites most predictive of fracture risk. Some facilities also scan the forearm.
The whole thing takes 10–15 minutes. Radiation exposure is approximately 1–10 microsieverts, which is roughly 1/10th of a chest X-ray or about the same as a cross-country flight. There are no injections, no contrast dye, and no recovery time.
Quick Prep Checklist
- Stop calcium supplements 24 hours before the scan
- Wear loose clothing without metal (elastic waistband, no underwire bras)
- Tell your doctor if you’ve had a barium study or contrast CT in the past 7–14 days
- Bring previous DEXA results if switching facilities — comparing scans from different machines is unreliable
How Often Should You Repeat the Test?
This depends on your initial results. General guidance from the NOF and clinical practice:
- Normal T-score (above −1.0): Rescreen in 10–15 years
- Mild osteopenia (−1.0 to −1.5): Rescreen in about 5 years
- Advanced osteopenia (−1.5 to −2.4): Rescreen in 1–2 years
- Osteoporosis or on treatment: Rescreen every 1–2 years to monitor response
A landmark study published in the New England Journal of Medicine (2012) followed nearly 5,000 women and found that those with normal bone density could safely wait 15 years before rescreening, while women with moderate osteopenia needed follow-up within 5 years.
When to See a Doctor
Don’t wait for a fracture to bring up bone health. Schedule a conversation with your doctor if:
- You’re a woman approaching 65 or a man approaching 70 and haven’t discussed screening
- You’ve lost more than 1.5 inches of height (a sign of vertebral compression fractures)
- You’ve broken a bone from a minor fall or low-impact event after age 50
- You’re taking medications known to cause bone loss (steroids, aromatase inhibitors, PPIs long-term, certain anti-seizure drugs)
- You have a strong family history of osteoporosis or hip fracture
Ask specifically: “Based on my risk factors, should I get a DEXA scan now or can it wait?” That single question can change the trajectory of your bone health.
Frequently Asked Questions
Is a bone density test covered by insurance?
Medicare covers a DEXA scan once every 24 months for women aged 65+ and for anyone meeting certain risk criteria. Most private insurers follow similar rules. If your doctor documents specific risk factors, coverage for younger patients is usually approved. Without insurance, expect to pay $100–$300 out of pocket.
Can I improve my T-score once it’s low?
Yes. Bisphosphonates like alendronate can increase spine bone density by 5–8% over 3 years. Weight-bearing exercise, adequate calcium (1,000–1,200 mg/day from food and supplements combined), and vitamin D (800–1,000 IU/day) also help preserve and modestly improve density. The key is that treatment works best when osteoporosis is caught early — another reason screening matters.
Are there alternatives to the DEXA scan?
Quantitative CT (QCT) and peripheral ultrasound devices exist, but central DEXA of the hip and spine remains the gold standard for diagnosis and the basis for the WHO’s T-score classification. Heel ultrasound can be a useful screening tool at health fairs, but a low result should always be confirmed with a proper DEXA.
Why don’t guidelines recommend routine screening for younger women?
Peak bone mass is typically reached by age 30, and significant age-related bone loss in women accelerates after menopause due to estrogen decline. Screening at 40 in a woman without risk factors would almost always show normal results and wouldn’t change management. The cost-effectiveness of screening improves dramatically at 65 because that’s when fracture risk rises steeply.
Does the DEXA scan hurt?
Not at all. There are no needles, no enclosed spaces, and no loud noises. You simply lie still on a table for about 10 minutes. It’s one of the easiest diagnostic tests in medicine.
