A pulmonary embolism is a blockage of an artery in the lungs that can be life-threatening. Symptoms of a pulmonary embolism can include chest pain, shortness of breath, a rapid heart rate, and coughing up blood. Diagnosis is usually based on a physical examination, an imaging test, and a blood test. Treatment typically involves giving anticoagulants to prevent further clotting, and in some cases, a procedure to remove the clot.