- Aortic dissections occur when blood tears the inner layer of the aorta and flows down between the layers, splitting them apart. This creates a false lumen that can expand and rupture the aorta. - Risk factors include hypertension, connective tissue disorders like Marfan syndrome, and family history. The intimal tear allows blood to dissect the medial layers, often extending throughout the aorta. - Clinical symptoms include severe chest or back pain. Prognosis has improved with surgical techniques to repair the aorta before rupture occurs.