All About Bone Density Tests

A bone density test, which is also referred to as a DXA scan or densitometry, can determine whether you are at risk of osteoporosis or currently have have osteoporosis. What is osteoporosis? Osteoporosis is a disease that causes fragility in bones and makes them much more likely to break.

In a bone density test, an X-ray is used to measure how much calcium and other bone minerals are in a particular segment of bone. The test is used to predict an individual's risk of fracture, to confirm a diagnosis of osteoporosis after a broken bone or to monitor treatment for osteoporosis.

According to the Mayo Clinic's site, The National Osteoporosis Foundation recommends bone density testing if:

• You're a woman age 65 or 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 between age 50 and 70 with one or more risk factors for osteoporosis
• You're older than age 50 and you've experienced a broken bone
• You're a postmenopausal woman and you've stopped taking estrogen therapy or hormone therapy

You can expect your bone density test to be quick, painless and easy, with no real preparation needed.  A central (a large machine on which you lie down) or peripheral device (small, portable machine that measures bone density on the periphery of your skeleton) is usually used to measure bone density, and the test is commonly done on thigh bones, wrist or forearm bones or the bones of the lower spine.

The results of a bone density test are reported as a T-score number and a Z-score number. The number of units that your bone density is above or below the average is measured by the T-score, and the number of standard deviations above or below what's normally expected for someone of your weight, sex, race or age is measured by the Z-score.

In the past, osteoporosis could only be detected after you broke a bone. Thankfully, today a bone density test allows you to find out your risk of breaking bones before it occurs.