The literature addressing the relationships between biological and social factors in the etiology of multiple chronic diseases occuring simultaneously is presented. The rationale for studying such multiple outcomes is presented in terms of providing a realistic appraisal of the development of chronic diseases from a clinical perspective; i.e. persons with chronic illnesses often have more than one illness at the same time. Social processes related to the development of one joint disease outcome, namely clinically elevated blood pressure and heavy alcohol consumption patterns, are discussed, and emphasis is given to elaborating the role of stress and social support in the etiologic process. Several alternative models are presented to account for the etiology of the joint outcome, and a research agenda is suggested.