Embolism << EHM buh lihz uhm >> is a condition in which a blood vessel is blocked by material that has been carried there by the bloodstream. The blockage, which is called an embolus, may consist of a blood clot, air bubbles, clumps of bacteria, small drops of fat, cancer cells, or other foreign objects. The most serious embolisms occur in the brain, kidneys, or lungs. A blood clot, the most common cause of an embolism, usually forms in a leg vein and travels to other blood vessels. Air bubbles may result from a chest or lung injury. Bacteria from a serious infection can accumulate in the blood and cause an embolism. Bone fractures may damage fat tissue, releasing drops of fat into the blood. Cancer cells that have broken loose from a tumor may cause an embolus.
See also Stroke.