Women should get their first bone density test at age 65. If you have risk factors like a family history of osteoporosis, a previous fracture, or long-term steroid use, testing may be appropriate much earlier, sometimes starting in your 50s. For men, several major medical organizations recommend screening starting at age 70, though guidelines are less firmly established than for women.
Standard Screening Ages for Women and Men
The U.S. Preventive Services Task Force recommends routine bone density screening for all women aged 65 and older, regardless of risk factors. This is a Grade B recommendation, meaning there’s good evidence that screening at this age prevents fractures. No additional criteria need to be met. If you’re a woman who has reached 65, a scan is appropriate.
For men, the picture is less clear-cut. The USPSTF says there isn’t enough evidence to make a blanket recommendation for or against screening in men. However, the Endocrine Society recommends screening all men aged 70 and older, plus men between 50 and 69 who have specific risk factors. These include low testosterone, chronic lung disease, overactive parathyroid or thyroid glands, delayed puberty, long-term use of steroids, alcohol abuse, or smoking. If you’re a man over 50 and any of those apply, it’s worth discussing a scan with your doctor rather than waiting until 70.
Risk Factors That Warrant Earlier Testing
Age-based guidelines are the starting point, but plenty of people need testing well before 65 or 70. The Bone Health and Osteoporosis Foundation recommends bone density testing for women aged 50 to 64 and men aged 50 to 69 who have one or more of these risk factors:
- A fracture after age 50. Breaking a bone from a minor fall or low-impact event (called a fragility fracture) is one of the strongest indicators of weakened bones. More than two-thirds of people over 50 who experience a fragility fracture turn out to have low bone density when tested.
- Family history of osteoporosis or fractures. A parent who broke a hip is an especially significant red flag.
- Smoking or heavy alcohol use. Both accelerate bone loss over time.
- Vitamin D deficiency. Without adequate vitamin D, your body can’t absorb calcium effectively.
- Low body weight. People with smaller frames carry less mechanical load on their bones, which can lead to lower density.
- Frequent falls. Even if you haven’t fractured yet, a pattern of falling raises fracture risk enough to justify a baseline scan.
- Conditions that affect nutrient absorption. Celiac disease, inflammatory bowel disease, and gastric bypass surgery can all impair calcium absorption.
Steroid Use and Bone Loss
Long-term use of corticosteroids (like prednisone) is one of the most common causes of bone loss that people don’t expect. The American College of Rheumatology recommends a bone density scan as soon as possible for anyone starting a course of glucocorticoids at a dose of 2.5 mg or more daily for longer than three months. That applies whether the steroids are prescribed for arthritis, asthma, lupus, or any other condition.
Steroid-related bone loss happens fast, often within the first few months of treatment. If your doctor starts you on a prolonged steroid course, don’t wait for your next routine checkup to bring up bone density. A baseline scan early in treatment gives you and your doctor a reference point for tracking any changes.
What Your Results Mean
A bone density test (called a DXA or DEXA scan) produces a number called a T-score, which compares your bone density to that of a healthy 30-year-old. The scale works like this:
- T-score of -1.0 or higher: Normal, healthy bone density.
- T-score between -1.0 and -2.5: Osteopenia, a milder form of bone loss that doesn’t always require medication but does need monitoring.
- T-score of -2.5 or lower: Osteoporosis, which typically calls for treatment to prevent fractures.
Your T-score alone doesn’t tell the full story. Doctors often use a tool called FRAX alongside your scan results. FRAX calculates your 10-year probability of a major fracture based on your age, sex, weight, and clinical risk factors. In some cases, a person with osteopenia and a high FRAX score will benefit from treatment, while someone with a slightly worse T-score but no other risk factors may only need lifestyle changes. Treatment is generally recommended for people with osteopenia whose 10-year risk of a major osteoporotic fracture is 20% or higher, or whose hip fracture risk is 3% or higher.
How Often to Retest
The answer depends almost entirely on your initial T-score. A landmark study published in the New England Journal of Medicine tracked older postmenopausal women over 15 years and found dramatic differences in how quickly bone loss progressed based on baseline results:
- Normal bone density or mild osteopenia (T-score above -1.5): Fewer than 10% of women developed osteoporosis within about 15 years. Rescreening every 15 years or so is reasonable.
- Moderate osteopenia (T-score between -1.5 and -2.0): About 10% developed osteoporosis within 5 years. Rescreening every 5 years makes sense.
- Advanced osteopenia (T-score between -2.0 and -2.5): 10% transitioned to osteoporosis within roughly 1 year. Annual testing is appropriate.
If you’re already on osteoporosis medication, your doctor will likely order follow-up scans to check whether treatment is working. The intervals vary, but every one to two years is typical during active treatment.
Medicare and Insurance Coverage
Medicare Part B covers a bone density test once every 24 months if you meet at least one qualifying condition: you’re a woman with estrogen deficiency and osteoporosis risk, your imaging suggests possible bone loss or vertebral fractures, you’re taking or about to start prednisone or similar steroids, you’ve been diagnosed with primary hyperparathyroidism, or you’re being monitored during osteoporosis treatment. More frequent testing can be covered if your doctor documents it as medically necessary.
Most private insurance plans follow similar criteria, though specifics vary. If you’re under 65 and your doctor recommends a scan based on risk factors, the order itself usually satisfies the insurer’s requirement for medical justification.
How to Prepare for a DXA Scan
The scan itself is quick and painless, typically taking 10 to 20 minutes. You lie on a padded table while a low-dose X-ray arm passes over your hip and spine. The radiation exposure is extremely small, far less than a standard chest X-ray.
To get accurate results, stop taking calcium supplements, multivitamins, and vitamin D for 24 hours before your appointment. These can interfere with the reading. Wear loose, comfortable clothing with no metal, and remove jewelry before the scan. There’s no fasting required and no injection involved. You can drive yourself home and resume normal activity immediately.