Osteoporosis is a disease in which bones become fragile and more likely to break. If not prevented or left untreated, osteoporosis can progress painlessly until a bone breaks. These broken bones, known as fractures, occur typically in the hip, spine and wrist. In the U.S. today, 10 million individuals already have the disease and 18 million more have low bone mass, placing them at increased risk for osteoporosis. Eighty percent of those affected by the disease are women.
Because osteoporosis can be so difficult to detect, your doctor may recommend a bone density test. It is the most practical way to accurately measure the density of your bones and can be useful in helping your doctor diagnose the disease, especially early on. Repeated over time, it can also help your doctor track your rate of bone loss. Bone density is important as low bone mass is the most accurate predictor of an increased risk for broken bones.
There are several types of bone density tests available. Dual-Energy X-Ray Absorptiometry (DEXA) is one that involves an extremely small dose of radiation, less than one-tenth the dosage of a chest x-ray. DEXA is the most widely used and provides a highly accurate bone density measurement. DEXA can measure bone density at several central skeletal sites, including the lumbar, spine and the hip. These are the most clinically significant sites because they are subject to the most crippling fractures.