The strengthening and hardening of a bone in areas where calcium has been deposited.

Nearly all calcium entering the body is deposited in bones and teeth. The remaining calcium is dissolved in the blood. When a disorder affects the balance between calcium and other minerals or chemicals in the body, calcium can be deposited in other parts of the body, such as arteries, kidneys, lungs, and brain, and can cause problems in their normal function. Calcifications can usually be diagnosed using x-rays.