BackgroundThe experience of unpleasant sensations associated with the presence of symptoms prompts self-care or help seeking to obtain explanations for the symptoms, manage emotional responses, or obtain treatment for symptom alleviation and elimination.ObjectiveThe purpose of this article is to summarize and comment on three existing symptom theories, with special attention to temporal factors.MethodsExisting theories are synthesized as the time dimensions of symptom experiences and symptom management processes are elucidated. Clinical examples and findings from empirical studies illustrate critical points.DiscussionExisting theories describing the symptom experience and the process of symptom management refer implicitly to the role of time or use limited dimensions of time. Symptom experiences in time (SET) theory is proposed as a synthesis and extension of existing theories. The SET theory conceives the symptom experience as a flow process that explicitly incorporates temporal dimensions. Four dimensions of time are recognized: clock-calendar, biologic-social, perceived, and transcendent time. The four temporal dimensions are placed against a backdrop of “meaning-in-time” that brings forth the potential for transformation in a symptom experience. Increasing sophistication in design, measurement, and data analysis is required to test and evaluate SET theory-based propositions.ConclusionsThe SET theory extends previous work by incorporating multiple temporal dimensions that reflect the human experience of health and illness manifested in the expression and management of symptoms.