In this contribution to the longstanding risk theory debate on optimal self-protection, we aim to bridge the gap between the microeconomic modeling of self-protection, in the wake of Ehrlich and Becker (1972), and the Health Belief Model, a conceptual framework extremely influential in Public Health studies (Janz and Becker, 1984). In doing so, we highlight the crucial role of risk perception in the individual decision to adopt a preventive behavior towards a generic health risk. We discuss the optimal prevention effort engaged by an agent displaying either imperfect knowledge of the susceptibility (probability of occurrence) or the severity (magnitude of the loss) of a health hazard, or facing uncertainty on these risk components. We assess the impact of risk aversion and prudence on the optimal level of self-protection, an issue at the core of the risk and insurance economic literature. Our results also pave the way for the design of efficient information instruments to improve health prevention when risk perceptions are biased.