Lindsey Graham died of a suspected aortic dissection. What is that?

A dissection occurs when "the inner layer [of the aorta] rips," he says. "It's like a three-ply hose and when the inner layer rips, the aorta starts to unravel." An interior rip can cause the giant vessel's layers to come apart, disconnecting the attached, smaller blood vessels, leading to bleeding. A complete rupture can cause someone to bleed to death in a matter of minutes, Roselli says.