thromboembolism

the situation in which a blood CLOT ( THROMBUS ) forms in one part of the CIRCULATION , usually a deep VEIN in the leg ( PHLEBOTHROMBOSIS ), and a portion breaks off and becomes lodged elsewhere, causing a total blockage ( EMBOLISM ). The embolism often involves the pulmonary ARTERY or one of its branches, and this is known as PULMONARY EMBOLISM .