An aneurysm is a localized, abnormal dilation of a blood vessel, often an artery, caused by a weakness in the vessel wall. This bulging can lead to serious complications, including rupture, which can result in internal bleeding and potentially life-threatening situations. Aneurysms can occur in various parts of the body, with common types including cerebral aneurysms in the brain and abdominal aortic aneurysms in the abdomen. Early detection and monitoring are crucial for managing the condition effectively.