?Pulmonary embolisms are the second leading cause of sudden death in the United States. A pulmonary embolism is a blood clot which, in approximately 90% or more of the cases, develops in the lower extremities, frequently the calf, which travels to the heart and lungs. Risk factors for pulmonary embolism include pregnancy, birth control pills, hormone therapy, inactivity, obesity, major surgery to repair broken bones, and joint replacements. If not promptly diagnosed and treated, a pulmonary embolism can cause death by cutting off the oxygen supply to the lungs. The signs and symptoms of pulmonary embolism can include shortness of breath (typicnia), rapid heart rate (tachycardia), increased respiration rate, pain in the calf without any injury, and swelling or edema in the lower leg. If blood gases are drawn at the hospital, they can indicate increased carbon dioxide, and decreased oxygen saturation. A physician who suspects a deep vein thrombosis (DVT) should order a venous duplex scan which will show the DVT of the leg through an ultrasound. In addition, a CT scan or VQ scan should be ordered to diagnose the pulmonary embolism. If diagnosed, anti-coagulation therapy such as heparin or coumadin will be ordered and the survival rate, if detected promptly, is more than 95%.