Why is a bone density test useful?
A bone density test measures how much bone you have. The size and density of a bone influences strongly whether or not it will break, so measuring the density of a bone can be used to estimate its risk of breaking. However, there is no need to measure the density of every bone in the body. Osteoporosis is a global disease that affects the whole skeleton, some parts more than others, but all to some extent, so that measuring any one bone helps to estimate your overall risk for fracture.
