A pulmonary embolism occurs when a venous clot (thrombus) dislodges and travels through the circulatory system and becomes trapped in the lungs. The resulting blockage prevents oxygen exchange and can cause difficulty breathing, coughing up of blood and even instant death if the clot is big enough.
I had a deep venous thrombosis in my leg and then it dislodged which gave me a pulmonary embolism. Then I died.
by The Troll May 05, 2006