An aneurysm is a bulge or ballooning in the wall of an artery. There are several types including abdominal aortic aneurysms (AAA), thoracic aortic aneurysms, cerebral (brain) aneurysms, and peripheral aneurysms. AAAs are the most common and occur in the abdominal portion of the aorta. Risk factors include age, male gender, smoking, family history, and certain diseases. Diagnostic tests include ultrasound, CT scan, MRI, and angiography. Treatment options are medical management to control risk factors as well as open or endovascular surgery to repair the aneurysm. Complications can include hemorrhage, ischemia, stroke, and infection.