Osteoporosis is a condition that increases with age. It is a major cause of weak bones, causing fractures resulting from minor injury, which could be preventable with treatment. Osteoporosis, in the absence of fracture, has no symptoms. A number of medical conditions and medications can increase bone loss, making it important to diagnose osteoporosis early, to prevent fractures from occurring. The DXA scan measures the bone mineral content and provides information to your doctor as to whether you have lost a small amount of bone (osteopenia) or a more significant amount (osteoporosis), compared with a young normal population, and people of the same age and sex as you. This informs your doctor about your risk of having a fracture, and assists in monitoring bone loss and in planning any preventative therapy or medical treatment.
What is a Bone Mineral Density Scan?
A dual-energy X-ray absorptiometry scan (DXA), or bone density scan, is a special type of X-ray that measures bone mineral density (BMD). It provides information about bone strength or fragility and the risk of fractures or broken bones. The higher the density, generally, the lower the risk of fracture.
The spine and one or both hips are routinely scanned. The forearm might also be scanned if either the hip or spine is unavailable (usually due to surgery). As any condition affecting bone density tends to affect the whole skeleton, a snapshot of a few sites is sufficient to establish the overall bone density. The BMD at the hip and spine has been shown to be the best way of predicting the risk of fracture.
You might be referred for this test if you have:
reached menopausal age/men over the age of 65;
a medical condition that could weaken your bones;
a medical condition requiring high doses of cortisone, long periods of bed rest or major weight-loss;
you might have had a recent fracture after a minor injury or fall that in other persons would not have broken a bone;
an X-ray image or picture taken for another reason has shown that the vertebrae in your spine are weakened and losing height.