What is an aneurysm?

An aneurysm is defined as an excessive localized enlargement of an artery that occurs due to the weakening of the arterial wall. This abnormal ballooning can happen in any artery in the body but is most commonly found in the aorta, the brain (cerebral aneurysm), and the leg arteries. The wall of the artery develops a bulge caused by high blood pressure or other factors that create stress on the artery wall. If an aneurysm grows large, it carries the risk of rupture, which can result in serious complications or even death.

Understanding this definition illustrates why the choice identifying an aneurysm as an excessive localized enlargement of an artery is correct. Other options describe different vascular issues, such as tears, blockages, or abnormal rhythms, which do not specifically or accurately define what an aneurysm is.