This article examines the role and meaning of susto (fright) in Mexican Americans’ explanatory model (EM) of type 2 diabetes. This analysis is based on a study of the health beliefs about type 2 diabetes mellitus among Mexican Americans living in El Paso County, Texas, on the U.S.-Mexico border. Susto was described as an event that could change the bodily state, causing a susceptible person to be more vulnerable to the onset of type 2 diabetes after some unspecified time. The study results illustrate the integration of multiple etiologies into Mexican Americans’ EMs of diabetes and illustrate how the environment affects the way in which these explanations are manifested. Acculturation of biomedical system beliefs into the traditional Mexican health belief system has resulted in a synthesis of both systems and a blending of the participants’ explanation of type 2 diabetes.