Key Points

• A pulmonary embolism (PE) is a sudden blockage in a lung artery. The blockage usually is due to a blood clot that traveled to the lung from a vein in the leg. The clot blocks blood flow to part of the lung. If a blood clot is large, or if there are many clots, PE can cause death.
• In most cases, PE is a complication of a condition called deep vein thrombosis (DVT). In DVT, blood clots form in the deep veins of the body-most often in the legs. These clots can break free, travel through the bloodstream to the lungs, and block an artery.
• At least 100,000 cases of PE occur each year in the United States. PE is the third most common cause of death in hospitalized patients. If left untreated, about 30 percent of patients who have PE will die.
• The greatest risk for PE occurs in people who have DVT or a history of it, or who have had PE before. PE occurs equally in men and women. Your risk for PE doubles every 10 years after age 60.
• Signs and symptoms of PE include unexplained shortness of breath, problems breathing, chest pain, coughing, or coughing up blood. Other symptoms may be linked to DVT, such as swelling of the leg. It's possible to have PE and not have any signs or symptoms.
• Your doctor will diagnose PE based on your medical history, a physical exam, and the results from tests.
• PE is treated with medicines, procedures, and other therapies. The main goals of treating PE are to stop the blood clot from getting bigger and keep new clots from forming. Treatment varies depending on how severe your symptoms are.
• Preventing PE begins with preventing DVT. Knowing whether you're at risk for DVT and taking steps to lower your risk are important. Contact your doctor right away if you have any signs or symptoms of PE or DVT.
• PE usually is treated in a hospital. After leaving the hospital, you may need to take medicine at home for 6 months or longer. It's important to take your medicines as prescribed, get ongoing care, and contact your doctor if you have signs or symptoms of bleeding (a side effect of some medicines for PE) or another PE.