The concept of disease has been dynamic throughout history and has responded to the different historical, political, and cultural contexts of humanity. Neuraltherapeutic medicine is a complex medical approach that aims to understand diseases in a way that goes beyond the limitations of the traditional biomedical model. The chapter points out the characteristics of biomedicine described as reductionism, analytical methodology, and dualism. In contrast, the chapter proposes the incorporation of theoretical elaborations such as complex systems, nonlinear dynamics, emergence, and evolution. These notions provide medicine with diverse approaches, from an epistemological perspective, regarding biological and vital processes, particularly in relation to people’s suffering. For neuraltherapeutic medicine, the fundamental objective of accompanying the process of illness requires an understanding of suffering as a biographical experience that incorporates both the biological part and the meaning attributed to that experience. Phenomenology nourishes the development of medical knowledge with humanism and achieves a more horizontal, dialogical, and consensual doctor–patient relationship.