n. the interruption of blood flow due to blockage of a vessel by an embolus, material formed elsewhere and carried by the bloodstream to the site of obstruction. The embolus may be a blood clot, air bubble, fat globule, or other substance, such as a clump of bacteria or tissue cells. An embolus usually occurs at a point where a blood vessel branches or narrows. The symptoms are those associated with a disruption of the normal flow of fresh blood to a part of an organ and include pain, numbness, and loss of body warmth in the affected area. An embolus in a coronary artery may cause a fatal heart attack; in the brain, the result is an embolic stroke.