Central, but largely limited to the somatic level, approaches to explaining disease are represented by the biomedical disease model and the risk factor model. The former assumes a cause-and-effect relationship and identifies possible causes, among others, in infections or biochemical dysfunctions, which is why its treatment approaches aim to eliminate deviations from the norm. The increase in chronic and non-communicable lifestyle diseases prompted the further development into the risk factor model, which does not begin with early symptoms of disease, but rather with the convergence of certain risk factors. Despite the contributions of both models to the development of treatment and prevention measures, their greatest shortcoming is the neglect of equally relevant psychosocial factors. In this chapter, both models will be outlined in their essential features and critically evaluated.