Acute aortic syndrome (AAS) describes a range of severe, painful, potentially life-threatening abnormalities of the aorta.[1] These include aortic dissection, intramural thrombus, and penetrating atherosclerotic aortic ulcer.[2] AAS can be caused by a lesion on the wall of the aorta that involves the tunica media, often in the descending aorta.[3] It is possible for AAS to lead to acute coronary syndrome.[4] The term was introduced in 2001.