A bone density test - also called densitometry or DEXA scan - is used to determine whether you have or are at risk of osteoporosis. Osteoporosis causes bone fragility and proneness to bone fracture.
Densitometry technology can now determine osteoporosis before a fracture occurs, allowing implementation of an appropriate prevention and strengthening regimen. Bone density testing accurately predicts fracture risk by using x-rays to measure the volume of calcium and other bone minerals in a particular segment of bone.
Bone density tests are not the same as bone scans, which require an injection beforehand and are most commonly used to detect fractures, cancer, infections and other bone abnormalities.
The National Osteoporosis Foundation recommends bone density testing if:
- You're a woman age 65 and older
- You're a postmenopausal woman under age 65 with one or more risk factors for osteoporosis
- You're a man age 70 or older
- You're a man age 50 to 70 with one or more risk factors for osteoporosis
- You're older than 50 and you've experienced a broken bone
- You're a postmenopausal woman and you've stopped taking estrogen therapy or hormone therapy
While there is no clearly defined optimal interval for repeat bone density tests, two or more years may be needed between tests to reliably measure change in bone density. Consult with your physician.
Osteoporosis Risk Factors
Osteoporosis risk factors include:
- Ethnicity (White and Southeast Asian women have highest risk)
- Low body weight (under 125 lbs. if you're average height)
- Personal history of fractures after age 40
- Parental history of osteoporosis or hip fractures
- Using certain medications that can cause bone loss, especially steroids