What getting sick means. The concepts of health, disease and death have intrigued man since the beginning of time and are continually evolving. In the nonwestern societies the models which have been proposed for the etiology of disease have a dichotomous view of disease causation which is derived from either natural or supernatural forces. In the Western societies these concepts are well defined. The numerous advances in the fields of genetics and molecular biology have added a new dimension to the understanding of the various factors involved in the pathogenesis of disease processes. These advances have allowed a greater understanding of numerous disease processes including the inborn errors of metabolism, endocrine disorders and human neoplasia. Several recent advances in the areas of molecular biology and physiology allowing this increased understanding of human disease are presented. 