title: The signs, symptoms and prevention of pulmonary embolism.
abstract: Pulmonary embolism is a sudden occlusion of blood flow to the lungs by a blood clot that has usually arisen from a deep vein thrombosis. Clots can break off and then travel through the heart to the lungs. Large clots lodge in the main pulmonary artery, causing a potentially fatal blockage. Smaller clots travel to the lung periphery where they may cause inflammation that results in pleuritic chest pain.