This article is a 2-part series about patients with aortic emergencies. Patients with acute aortic disease who present to the emergency department represent some of the highest acuity patients that emergency clinicians will ever encounter in acute care settings. Part 1 focuses on aortic aneurysms in the thorax or abdomen. An aortic aneurysm involves transverse dilatation, leading to rupture and hemorrhage. Diagnosis is largely based on clinical presentation and carefully selected imaging studies. Emergency interventions are guided by whether or not the patient is hypertensive or in shock. For patients in shock, attention should focus on restoring intravascular volume while not generating excessive blood pressure. Open surgical intervention or endovascularly placed stent grafting should then be expedited. Both options are not without complications, most commonly being stroke, paraplegia, and death. Part 2 will explore aortic dissection.