Research on elders' health behavior has largely ignored the stage between experiencing a bodily change and defining it as an illness. This paper addresses the question of what explains such definitions of bodily complaints as illness symptoms. The issue is examined in a longitudinal study with a random sample of 350 community dwelling persons aged 65 and over. Multiple regression was used to analyze the effects of external stresses, psychological factors and health attitudes as well as contextual variables, on three types of illness representations. These consisted of giving the bodily changes an illness label, initiating contact with a physician, and/or using some form of self care. These illness representations were treated as outcome variables singularly and in combination. The findings revealed that the overall frequency of a person's bodily changes was the best predictor of an illness designation. Other significant predictors at Time 4 of the study included belief in the seriousness of a complaint, the occurrence of prior illness representations and self-assessed health. This research study on the elderly is unique in that it seeks to explain, within a longitudinal design, the intermediate step between the experience of a bodily change and the definition of the change as an illness.