Osteoporosis

The diagnosis of osteoporosis is often not made until a typical osteoporotic fracture has occurred. However, patients can be diagnosed earlier by measuring bone density. This is most commonly done using an X-ray technique called a DEXA (dual energy X-ray absorptiometry) scan. The bone density of the person is then calculated as the number of standard deviations (SD) above or below the average value of a healthy young adult. The lower the bone density, the higher the risk of fracture. The WHO (World Health Organization) defines osteoporosis as a bone mineral density 2.5 SD below the young adult average. Other methods such as heel ultrasound and CT scans can also be used, although they have not been as extensively studied. Screening for osteoporosis is a controversial area and guidelines vary, but all recommend individual consideration of the person's risk factors and the treatment being considered.