How is bone density measured?
There are a variety of ways to measure bone density, but to use the recommended WHO classification, it needs to be measured with a technique called central DEXA, which is an abbreviation for dual energy x-ray absorptiometry. This is a painless test that takes about five minutes. It has very little radiation exposure. It measures the central skeleton, the spine and the hips, which are sites that are commonly affected by osteoporotic fractures. There are machines out there that will measure bone density in the heel, in the finger, in the forearm. The problem with those devices is that the scores that we get with them cannot be used with the WHO numbers. So if you have a heel test and you’re at -1.5, your hip might be -2.5. So these tests tend to under-diagnose osteoporosis. When should bone density be tested? It’s important to think about bone density testing in two different frameworks: as a medical test and as a screening test. It’s certainly an appropriate medical test in people who h
