What is a bone density scan?
A bone density scan, or Dual-energy X-ray Absorptiometry (DXA), is a quick and painless procedure that measures bone mineral density (BMD). Unlike a standard X-ray that provides images, a DXA scan provides a precise measurement of your bone strength. By sending a low dose of X-rays through your body, it determines the amount of calcium and other minerals present in the bones, most commonly focusing on the hip and spine. The resulting score (T-score) is used to diagnose osteoporosis, predict future fracture risk, and monitor the effectiveness of any treatment.
Official screening recommendations by age and gender
Deciding when to get a bone density scan depends largely on your gender and age, though individual health circumstances are also critical. Medical organizations provide general guidelines to help patients and doctors navigate this process.
For Women
- Age 65 and older: All women in this age group are recommended for routine bone density screening, regardless of risk factors.
- Postmenopausal women under 65: Screening is recommended if you have one or more risk factors for osteoporosis. This includes low body weight, a prior fracture, or a parent with a hip fracture.
For Men
- Age 70 and older: Many medical organizations, including the National Osteoporosis Foundation and the Endocrine Society, recommend routine screening for men in this age group.
- Men aged 50-69: Screening is advisable if risk factors for osteoporosis are present. These factors can include lifestyle choices or underlying medical conditions.
Key risk factors that warrant earlier screening
While age is a significant factor, many individuals may need to consider a bone density scan sooner due to other risk factors. It is essential to discuss these with your healthcare provider to determine the best timing for you.
- History of fracture: Breaking a bone from a minor fall after age 50 is a strong indicator of weakened bones and a need for a scan.
- Medications: Long-term use of certain drugs, such as corticosteroids (like prednisone), some anti-seizure medications, and breast or prostate cancer treatments, can accelerate bone loss.
- Family history: A family history of osteoporosis, especially if a parent or sibling broke a hip, increases your own risk.
- Low body weight: Being underweight (typically defined as less than 127 pounds) or having a small, thin body frame can put you at higher risk.
- Medical conditions: Certain chronic illnesses can increase osteoporosis risk. These include rheumatoid arthritis, celiac disease, chronic liver or kidney disease, and type 1 diabetes.
- Significant height loss: Losing 1.5 inches or more in height can signal vertebral fractures caused by osteoporosis.
- Lifestyle factors: Smoking and excessive alcohol consumption negatively impact bone health.
How your doctor assesses your fracture risk
When evaluating your need for a bone density scan, your doctor will not only look at your age and risk factors but may also use a clinical risk assessment tool, such as the FRAX tool. FRAX estimates your 10-year probability of experiencing a major osteoporotic fracture. This helps determine whether treatment is needed, especially for individuals with osteopenia (low bone mass).
DXA vs. peripheral bone density tests
While central DXA scans of the hip and spine are the gold standard for diagnosis, you may encounter different types of bone density measurement devices. Peripheral devices measure bone density in the wrist, finger, or heel and can be found at some health fairs or doctor's offices. However, these are often used for initial screening and are less accurate than a central DXA. If a peripheral test indicates low bone density, your doctor will likely recommend a follow-up central DXA for a more precise diagnosis.
A comparative look: Central DXA vs. Peripheral Testing
| Feature | Central DXA Scan | Peripheral Test (pDXA) |
|---|---|---|
| Location | Hip and Spine | Wrist, Finger, or Heel |
| Accuracy | High; considered the gold standard | Moderate; primarily for screening |
| Purpose | Diagnoses osteoporosis, monitors treatment, assesses fracture risk | Screens for low bone mass; may need confirmation with Central DXA |
| Cost | Higher | Lower |
| Availability | Hospitals, imaging facilities | Doctor's offices, health fairs |
| Radiation | Very low dose | Very low dose |
The next steps after a bone density scan
Regardless of your bone density score, a comprehensive care plan should be developed in consultation with your doctor. If your results show normal bone density, maintaining a healthy lifestyle is key. For those diagnosed with osteopenia or osteoporosis, treatment and lifestyle adjustments are necessary to prevent fractures and slow bone loss. Treatment may include medication, increased calcium and vitamin D intake, and weight-bearing exercise. Your doctor will also advise on how often you should have repeat scans to monitor your bone health over time.
The importance of being proactive
Ultimately, knowing at what age should I get a bone density scan? is not just about a number; it is about being proactive with your health. The goal is to detect bone loss early, before a fracture occurs. For older women and men, or those with significant risk factors, a bone density scan is a critical tool for maintaining independence and quality of life as you age. By understanding the guidelines and discussing your personal risk with your healthcare provider, you can take control of your bone health.
For more detailed information on bone health, visit the Bone Health and Osteoporosis Foundation website at https://www.bonehealthandosteoporosis.org/.
