A pulmonary embolism is a blockage in an artery leading to the lungs, most often caused by a blood clot.
Pulmonary embolism most commonly occurs when a deep vein thrombosis (DVT) breaks loose in the leg or pelvis and travels through the bloodstream to the lungs. Risk factors for DVT include periods of being immobile (such as during bedrest), chronic illnesses (such as lung cancer) and surgery.
Common symptoms include severe sudden chest pain, shortness of breath and lightheadedness. Pulmonary embolism is a medical emergency that can be fatal if untreated.