Reviewed by Joseph Maloney, M.D.Pulmonary embolism (PE) occurs when a blood clot (embolus) travels though the venous system to the lung and lodges in the pulmonary vessels. These emboli can arise in the leg, pelvis, arm, or heart. These emboli can arise in the leg, pelvis, arm, or hear and travel to the lung’s arteries where it becomes lodged in an artery. Pulmonary emboli are responsible for more than 50,000 deaths in the U.S. each year.
Occasionally, when a blood clot or other blockage is present in the circulatory system somewhere in the body, small pieces of the clot may break off and travel to the lung, where they block off blood flow to lung tissue and cause vasospasm and bronchospasm. Pulmonary emboli are very often fatal, and any symptoms should be treated as emergencies in need of immediate medical attention. Repeated embolism can lead to heart failure.
Risk factors for the development of PE include:
prolonged bed rest
surgery, especially reproductive tract surgery and heart surgery
immobility and sedentary lifestyles
presence of underlying vascular disease, such as deep vein thrombosis (DVT)
cancer
pregnancy
hormone therapy treatments
irregular heart beat
injury
genetic tendency to form clots more easilyPulmonary embolism occurs most often in people over the age of 60, and with far greater frequency in people who have been hospitalized for prolonged periods of time for heart or lung problems.