See also: List of states and territories of the United States. This table includes abbreviations for three independent nations related to the United States through Compacts of Free Association, and other comparable postal abbreviations, including those now obsolete. Codes and abbreviations for U.S. states, territories and other regions.
Pulmonary embolism is the sudden blockage of a major blood vessel (artery) in the lung, usually by a blood clot . In most cases, the clots are small and are not deadly, but they can damage the lung. But if the clot is large and stops blood flow to the lung, it can be deadly.
1 Blood clots in the veins can cause inflammation (irritation) called thrombophlebitis.  Severe complications of deep vein thrombosis occur when a clot breaks loose (or embolizes) and travels through the bloodstream, causing blockage of blood vessels (pulmonary arteries) in the lung.