Analyses of 174 clinical incident events indicated that there were two types of aneurysmal disease, 151 aortic aneurysms and 23 aortic dissections. The baseline risk factors that predicted the clinical aortic aneurysms were the same factors that predicted aortic atherosclerosis in the same cohort, namely, high blood pressure, high serum cholesterol, and cigarette smoking. These same risk factors were also significantly associated with the occurrence of 27 aortic aneurysms among 293 autopsied men