Aneurysms occur in approximately 5% of the population. Risk factors include age greater than 65 years, male gender, hypertension, hyperlipidemia, peripheral artery disease (PAD), atherosclerosis, smoking, chronic obstructive pulmonary disease (COPD), and a family history of aortic aneurysm. Ninety percent of abdominal aneurysms are located in the infrarenal aorta (AAA) and 10% involve the descending and thoracoabdominal aorta (TAA). Aneurysms can occur in any vessel but are less common in the splenic, renal, and peripheral arteries. Many aneurysms are an incidental finding on physical exam or diagnostic testing done for another problem because they are usually asymptomatic.