BAsic information description A ballooning or bulge in the wall of a blood vessel (almost always an artery). It can affect the arteries in the chest, abdomen, brain, legs, or heart wall. Aneurysms have thin, weak walls and have a tendency to rupture (burst) and cause hemorrhage (bleeding). They occur most often in adults over age 55. frequent signs and symptoms Usually, there are no symptoms unless the aneurysm ruptures. Symptoms that occur depend on the artery affected. Thoracic...