From Reductionist Physiology to Regulatory Systems: A Systems Biology Interpretation of Chronic Multisystem Disorders

Abstract Modern medicine achieved extraordinary success through reductionist analysis: isolating genes, proteins, organs, and molecular pathways into increasingly precise domains of investigation. This framework transformed infectious disease management, surgery, pharmacology, and acute care. However, the contemporary rise of chronic multisystem disorders increasingly exposes the explanatory limitations of strictly component-based physiology. Conditions such as chronic pain syndromes, dysautonomia, fatigue disorders, functional gastrointestinal syndromes, sleep disturbances, anxiety-related physiological dysregulation, and medically unexplained symptoms frequently display diffuse, overlapping, and dynamically shifting characteristics that resist clean localization within isolated tissues or organs. This article proposes that many of these phenomena may be better interpreted through a Systems Biology framework in which the organism is understood as a continuously adaptive regulatory network operating across interacting mechanical, neural, immune, respiratory, vascular, metabolic, and behavioral scales simultaneously. Rather than viewing chronic dysfunction primarily as isolated structural pathology, Systems Biology reframes many persistent conditions as emergent regulatory states arising from prolonged adaptive pressures, altered system economics, and recursive physiological interactions. The growing convergence between mechanobiology, network physiology, autonomic regulation research, psychoneuroimmunology, and computational systems science suggests the emergence of a broader conceptual transition in medicine: from localized pathology toward dynamic organizational physiology.