On the Concept of Pain Chronicization: Clinical Observations and Neurobiological Inference.

Background: Pain chronicization is commonly used to describe the transition from acute to chronic pain driven by central mechanisms. Objective: To reassess its clinical relevance by comparing neurobiological models with patient observation. Methods: Conceptual analysis integrating experimental data and clinical experience. The analysis particularly considers animal models, human neuroimaging and ICD‑11 chronic pain categories. Results: While central sensitization is well established experimentally, clinical observation rarely shows a clear transition from acute to chronic pain. Chronic pain is typically heterogeneous, discontinuous and influenced by multiple factors. Neuroimaging findings are largely associative and lack temporal and causal definition. The distinction between chronic primary and secondary pain is clinically useful but does not demonstrate a biological conversion. Conclusion: Pain chronicization should be considered a theoretical construct rather than a clinically demonstrable process, and interpreted with caution in individual patients.