Most women should get their first DEXA scan at age 65. Men don’t have a formal screening recommendation yet, but many doctors order scans for men starting at age 70. If you have specific risk factors, though, you may need one much earlier. The timing depends on your sex, your medical history, and whether you’re taking certain medications.
The Standard Screening Age for Women
The U.S. Preventive Services Task Force recommends routine bone density screening for all women 65 and older. This is a blanket recommendation, meaning you don’t need any special risk factors to qualify. The goal is catching osteoporosis before a fracture happens, since bone loss is silent and you won’t feel it until something breaks.
For postmenopausal women younger than 65, the recommendation shifts to a risk-based approach. If you’ve gone through menopause and have one or more additional risk factors, your doctor should use a clinical risk assessment tool to estimate your fracture probability and decide whether a scan makes sense now rather than waiting until 65. Risk factors include low body weight, a parent who broke a hip, smoking, and excessive alcohol use.
One widely used tool is the FRAX calculator, which estimates your 10-year probability of a major fracture. In large screening studies, women whose FRAX score hit 15% or higher for major osteoporotic fracture were referred for DEXA scanning. Your doctor can run this calculation using basic information like your age, weight, and fracture history, sometimes without any blood work at all.
What About Men?
There’s no official consensus on when men should be screened. The USPSTF has stated that there simply isn’t enough data to determine whether routine screening in men provides a net benefit. In practice, many clinicians follow guidance from organizations like the Endocrine Society and order a first scan for men at age 70, or earlier if risk factors are present.
Men under 50 who experience a fragility fracture (breaking a bone from a minor fall or even just bending over) should get a DEXA scan promptly. That kind of fracture at a younger age is a red flag for an underlying cause of bone loss that needs investigation.
Medications That Call for Earlier Screening
Certain medications accelerate bone loss, and if you’re starting one, a baseline DEXA scan before or shortly after beginning treatment gives your doctor a reference point to track changes over time.
The biggest culprit is long-term corticosteroid use. If you’re taking the equivalent of 7.5 mg or more of prednisolone daily for three months or longer, you should have a bone density assessment. This applies to postmenopausal women and men over 50 especially, but even younger adults in their 30s and 40s on prolonged high-dose steroids may need scanning since significant bone loss can occur early in treatment. Conditions like giant cell arteritis or severe asthma sometimes require these doses for extended periods.
Other medications linked to bone loss include:
- Aromatase inhibitors used in breast cancer treatment
- Anti-seizure medications
- Hormone-suppressing injections (GnRH agonists) used for prostate cancer, endometriosis, or fibroids
- Long-term injectable contraceptives (depot medroxyprogesterone)
If you’re starting any of these, ask your prescribing doctor whether a baseline DEXA scan is appropriate. Patients under 85 on these medications often benefit from a pre-treatment scan so future bone loss can be measured against a known starting point.
Medical Conditions That Warrant a Scan
Several chronic diseases cause “secondary osteoporosis,” meaning bone loss driven by an underlying condition rather than aging alone. These conditions often justify screening well before the standard age thresholds.
Rheumatoid arthritis is one of the most common. Roughly one-third of people with rheumatoid arthritis develop osteoporosis, partly from the disease itself and partly from the corticosteroids often used to manage it. Celiac disease is another important one: the intestinal damage from gluten causes malabsorption of calcium and vitamin D, which quietly undermines bone strength over years. Overactive parathyroid glands (primary hyperparathyroidism) pull calcium from bone into the bloodstream, weakening the skeleton from the inside.
Other conditions that increase your risk include type 1 diabetes, hyperthyroidism, chronic kidney disease, and inflammatory bowel disease. Premenopausal women with osteoporosis and men under 50 with fragility fractures or low bone density on an initial scan should be evaluated for these secondary causes.
How to Read Your Results
If you’re a postmenopausal woman or a man 50 or older, your result comes as a T-score, which compares your bone density to that of a healthy 30-year-old of the same sex. The scale works like this:
- Above -1.0: Normal bone density
- -1.0 to -2.5: Osteopenia (lower than normal, but not yet osteoporosis)
- -2.5 or lower: Osteoporosis
Younger adults and premenopausal women receive a Z-score instead, which compares their density to others their own age. A very low Z-score prompts investigation into whether something other than aging is driving bone loss.
How Often to Repeat the Scan
Your first result determines when you need the next one. If your initial T-score is normal or shows only mild osteopenia (above -1.5), you can safely wait about 15 years before rescreening. That’s a longer interval than many people expect, and it means a 65-year-old woman with a good first scan may not need another until she’s 80.
Moderate osteopenia (T-score between -1.5 and -1.99) calls for a repeat scan in about five years. Advanced osteopenia (T-score between -2.0 and -2.49) warrants annual monitoring, since you’re close to the osteoporosis threshold and your doctor will want to catch any decline quickly. For women over 80, these intervals are typically shortened by about one-third because bone loss accelerates with age.
If you’re being treated for osteoporosis, follow-up scans are usually ordered every one to two years to check whether treatment is maintaining or improving your bone density.
What to Expect on Scan Day
A DEXA scan is quick and painless. You lie on a padded table while a low-dose X-ray arm passes over your body, typically scanning your hip and lower spine. The whole process takes about 10 to 15 minutes, and the radiation exposure is a fraction of what you’d get from a standard chest X-ray.
You can eat and drink normally beforehand. Wear loose, comfortable clothing without metal zippers, belts, or buttons, since metal interferes with the image. Skip your calcium supplements and any antacid tablets (like Tums) the morning of the exam, as undigested calcium in your system can artificially inflate your reading. No other preparation is needed.