An illustration of a blockage in an artery in the lungs,known as a pulmonary embolism. A pulmonary embolism is most often caused by a deep vein thrombosis,a blood clot (thrombus) in the deep veins of the legs or pelvis,which may break apart,creating an embolus which migrates to the lungs. A small embolus may not present any symptoms,and can dissolve in the lungs over time. A large embolus can result in sudden death if blood cannot reach a large portion of the lung,resulting in cyanosis,difficulty breathing,chest pain,heart palpitations and collapse |