Bone Density Testing
What is a bone density test?
A bone density test, also called bone densitometry or a DEXA/DEXA scan, is a safe, non-invasive way to measure the strength and mineral content of your bones. Using low-dose X-rays, this painless exam evaluates bone loss and identifies changes in bone density. The amount of radiation you receive is extremely low — comparable to what you’re naturally exposed to in a single week.
Bone densitometry is the standard method for diagnosing bone problems and assessing bone health, helping doctors detect issues before fractures or other complications occur.
How is a bone density test done?
A bone densitometry test is simple, painless and does not require injections or contrast.
- You may be asked to wear a gown and have your height and weight measured.
- Common areas scanned include the lumbar spine and hips, but other skeletal sites may be evaluated.
- The test uses a padded table, and you’ll lie on your back, breathing normally.
- Staying still during the scan is important to ensure accurate results.
The scan usually takes 15 minutes or less, and you can resume normal activities immediately. A radiologist interprets the results and shares them with your doctor.
What happens if you have low bone mass?
Low bone mass is the most accurate predictor of increased risk for fractures or broken bones. When bones weaken, you may notice symptoms such as:
- Back pain
- Changes in posture, like bending forward
- Loss of height over time
- Shortness of breath (not caused by heart or other conditions, indicating a potentially compressed spine)
Early bone loss often has no symptoms. For example, people with osteoporosis often aren't aware they have it until they break a bone.
Screening is essential to detect problems before serious damage occurs.
Does a bone density test detect cancer?
A standard bone density test DEXA or DXA scan isn't designed to detect or diagnose cancer. Its purpose is to measure bone mineral density and evaluate conditions like osteoporosis, osteopenia and fracture risk. While it assesses bone strength, it doesn't identify cancer cells, bone tumors or other malignancies.
Who Should Have a Bone Density Test?
Women: Screening is recommended at menopause or age 50 (whichever comes first) if you have risk factors, or by age 65 if you have no known risks.
Men: Screening is recommended at age 70 or earlier if risk factors are present.
Risk factors for bone loss include:
- Abnormal hormone levels
- Early menopause (before age 50)
- Family history of osteoporosis or parental hip fracture
- Increasing age (nearly 20% of women 50+ and 5% of men 50+ have osteoporosis, per the Centers for Disease Control and Prevention)
- Low body weight (under 120 lbs.)
- Personal history of bone fractures
- Progressive height loss or short stature (< />
- Prostate cancer or low testosterone in men
- Race (higher risk in white or Asian individuals)
- Use of medications that affect bone health, like diuretics, blood thinners or acid reflux/GERD medications
Bone Density Test FAQs
Bone densitometry is most commonly used to detect osteoporosis, a condition where bones gradually lose calcium and structural integrity, becoming fragile and prone to fractures. Osteoporosis affects women after menopause but may also be found in men.
- A bone density test can detect osteoporosis early, even before symptoms appear.
- Tracking bone density over time helps your doctor monitor bone loss and adjust treatment, if needed.
Preparation is minimal. Follow these guidelines:
- Eat and drink normally.
- Notify the technologist if you are or might be pregnant.
- Avoid barium or nuclear medicine exams for 72 hours before your test.
- Do not take calcium supplements, Tums, Rolaids, Pepcid, Vitamin D or multivitamins for 24 hours before the scan.
- Wear comfortable, loose-fitting clothing without metal (buttons, zippers, hooks, underwire bras).
- Remove jewelry and body piercings below the neck if possible.
The cost of a bone density test varies depending on several factors.
For patients with insurance, many plans — including Medicare — cover a bone density test if you meet certain age or risk-factor guidelines. Your out-of-pocket cost will depend on your specific benefits, such as deductibles or copays.