This article is an attempt to develop a formal model of single-actor illness self-regulation; that is, a goal-oriented, emotional and cog- nitive process based upon the creation of anticipated possible futures that trigger plans, decisions, and actions aimed at correct- ing the present state. The contemplated effects of the actions are represented as a transition operator that hopefully transforms the present state into a more desirable future state. As a case study, the model is applied to the self-regulation of glycemia in type-2 diabetes. An outline for the extension of the model to multi-agent, multidimensional self-regulation is also suggested.