PE is a blood clot in the lung, often caused by DVT (deep vein throbosis), which is a clot in a vein in the leg. If it loosens it shoots straight into the lung. Potentially life threatening if it affects a major pulmonary artery. Bosh will have to be on blood thinners PRONTO. Symptoms include shortness of breath, chest pain (not necessarily), and fast heart rate. It often affects patients in the hospital, who lay down all day (hence why we make patients walk all the time or wear those compressive things on their legs). I find it intriguing that Bosh, an athlete, gets a blood clot. Maybe he has some hypercoagulable disorder or something.