Bone Density Testing: Who Needs a DEXA Scan

Your bones might seem solid and unchanging, but they're actually living tissue that constantly breaks down and rebuilds. When this balance shifts and bones lose density faster than your body can replace it, osteoporosis develops—making bones fragile and prone to fractures.

Bone density testing, particularly the DEXA scan, provides an early warning system for osteoporosis. Understanding who needs this screening and what the results mean can help you protect your bone health and prevent life-altering fractures.

What Is a DEXA Scan?

DEXA (dual-energy x-ray absorptiometry) is the gold standard for measuring bone density. This painless, non-invasive test uses low-dose x-rays to measure the amount of calcium and other minerals in specific areas of your bone, typically your spine, hip, and sometimes your forearm.

The scan takes about 10 to 30 minutes. You simply lie on a padded table while a scanning arm passes over your body. There's no preparation needed, though you should avoid taking calcium supplements for at least 24 hours before the test, as they can interfere with results.

Understanding Your Results: The T-Score

Your DEXA scan results are reported as a T-score, which compares your bone density to that of a healthy 30-year-old adult—the age when bone density typically peaks.

What the numbers mean:

• T-score of -1.0 or above: Normal bone density
• T-score between -1.0 and -2.5: Low bone density (osteopenia)
• T-score of -2.5 or lower: Osteoporosis
• T-score of -2.5 or lower with a fracture: Severe osteoporosis

Each decrease of 1 in your T-score represents approximately 10-12% loss in bone density and roughly doubles your fracture risk. For example, a T-score of -2.0 indicates bones that are about 20% less dense than optimal and carry about four times the fracture risk of normal bones.

Who Should Get Tested

Major medical organizations recommend bone density screening for:

Women:

• All women age 65 and older
• Postmenopausal women under 65 who have risk factors
• Women who experience a fracture after age 50

Men:

• All men age 70 and older
• Men age 50-69 with risk factors
• Men who experience a fracture after age 50

Adults of any age who have:

• Broken a bone from a minor injury
• A medical condition associated with bone loss (like rheumatoid arthritis)
• Taken certain medications known to cause bone loss (like long-term corticosteroids)
• Lost height or developed a stooped posture
• Had a transplant

Risk Factors for Osteoporosis

Several factors increase your likelihood of developing low bone density:

Non-modifiable factors:

• Being female, especially post-menopause
• Age over 50
• Small, thin body frame
• Family history of osteoporosis or fractures
• Caucasian or Asian ethnicity
• Early menopause (before age 45)

Modifiable factors:

• Smoking
• Excessive alcohol consumption
• Sedentary lifestyle
• Low calcium and vitamin D intake
• Certain medications (corticosteroids, some cancer treatments, seizure medications)
• Medical conditions affecting nutrient absorption

If you have multiple risk factors, talk to your healthcare provider about whether earlier screening might be appropriate for you.

Why Bone Density Matters

Osteoporosis is often called a "silent disease" because bone loss occurs without symptoms. Many people don't know they have it until they suffer a fracture from a minor fall or even from routine activities like bending or coughing.

The consequences of these fractures can be serious. Hip fractures, in particular, can lead to loss of independence, chronic pain, and increased mortality risk. About 20% of older adults who break a hip die within a year from complications.

The good news: osteoporosis is largely preventable and treatable. Identifying low bone density early allows for interventions that can slow or stop bone loss and reduce fracture risk.

What Happens If You Have Osteopenia or Osteoporosis

If your DEXA scan shows low bone density, your healthcare provider will develop a treatment plan based on your individual risk. This might include:

Lifestyle modifications:

• Weight-bearing and resistance exercises to strengthen bones
• Ensuring adequate calcium (1,000-1,200 mg daily) and vitamin D (800-1,000 IU daily)
• Quitting smoking and limiting alcohol
• Fall prevention strategies at home

Medication:

For osteoporosis or high-risk osteopenia, your healthcare provider might recommend medication. Several effective options are available, from bisphosphonates to newer biologics, each with different dosing schedules and side effect profiles.

Monitoring:

You'll typically have follow-up DEXA scans every one to two years to monitor bone density changes and ensure treatment is working.

How Often Should You Be Tested?

If your first DEXA scan shows normal bone density and you don't have risk factors, retesting every 10 to 15 years may be sufficient. However, if you have osteopenia, more frequent screening—typically every two to five years—helps monitor changes.

If you have osteoporosis and are being treated, your healthcare provider will likely recommend testing every one to two years to track your response to treatment.

Questions to Ask Your Healthcare Provider

When discussing bone density testing, consider asking:

• Based on my age and risk factors, do I need a DEXA scan?
• What is my T-score, and what does it mean for my fracture risk?
• How does my bone density compare to my previous scans?
• What can I do to improve or maintain my bone density?
• Do I need medication, or can lifestyle changes be enough?
• When should I have my next bone density test?
• Should I see an endocrinologist or bone specialist?

The Bottom Line

Bone density testing is a straightforward way to assess your fracture risk and catch bone loss before it leads to serious consequences. While osteoporosis is common—affecting about 10 million Americans—it doesn't have to be inevitable.

If you're approaching or past the recommended screening age, or if you have risk factors for osteoporosis, talk to your healthcare provider about whether a DEXA scan is right for you. Early detection gives you the best opportunity to protect your bones and maintain your independence and quality of life for years to come.