Affecting more than 10 million Americans, osteoporosis can lead to bone fragility and an increased risk of fractures. Fortunately, a bone mineral density (BMD) can help detect osteoporosis in its early stages so that treatment can begin. What exactly does this test entail? At what age should you get this important test, and how often should it be repeated?

According to the National Osteoporosis Foundation (NOF), "A bone mineral density test uses a special machine to measure bone density. Some people also call it a bone mass measurement test. This test lets you know the amount of bone mineral you have in a certain area of bone."  Your physician uses this measurement to evaluate whether you need treatment for osteoporosis. Certain people are at more risk for developing osteoporosis than others.  These include people who are small and thin, of older age, female, or who consume a diet low in calcium and vitamin D. Also at higher risk are those who smoke and drink excessively.

According to NOF, physicians may also recommend a bone mineral density test for:

  • Women age 65 or older,
  • Men age 70 or older
  • Postmenopausal woman under age 65 with one or more risk factors for osteoporosis
  • Men age 50-70 with one or more risk factors for osteoporosis
  • Men and women after age 50 who has broken a bone
  • Women going through menopause and/or postmenopausal women who have stopped taking estrogen therapy (ET) or hormone therapy (HT)

Additional risk factors include:

  • Long-term use of certain medications including steroids (for example, prednisone and cortisone), some anti-seizure medications, Depo-Provera®
  • and aromatase inhibitors including Arimidex®)
  • Certain treatments for prostate cancer
  • Certain treatments for breast cancer
  • Overactive thyroid gland (hyperthyroidism) or taking high doses of thyroid hormone medication
  • Overactive parathyroid gland (hyperparathyroidism)
  • X-ray of the spine showing a fracture or bone loss
  • Back pain with a possible fracture
  • Significant loss of height
  • Loss of sex hormones at an early age, including early menopause
  • Having a disease or condition that can cause bone loss (such as rheumatoid arthritis or anorexia nervosa)

There are several types of BMD tests. DEXA (dual energy x-ray absorptiometry) testing is most often recommended, takes only about 15 minutes, is painless and patients can stay fully clothed.  Peripheral DEXA is done on the forearm, heel, finger or other part of an extremity and is commonly used for screening - to determine whether low bone mineral density is suspected. Central DEXA performed on the hip and spine is commonly used for diagnosis - to determine with more certainty if osteoporosis is present.

If osteoporosis is diagnosed, medication may be prescribed to stop bone loss, increase bone density, and/or rebuild bone-essentially strengthening them from the inside out.  It takes a while for enough minerals to deposit to show a dramatic difference on DEXA testing.  For that reason, most people are advised to repeat BMD testing every two years.

Early diagnosis and treatment for osteoporosis is the best defense against broken bones. Talk to your doctor about whether you're overdue for your BMD.