Chronic Low Back Pain: A Review of Diagnostic Algorithms, Pathophysiological Mechanisms, and Evidence-Based Management in Primary Care

Background and Objectives: This narrative review aims to evaluate the systemic challenges in managing Chronic Low Back Pain (CLBP) and establish an evidence-based operational framework for primary care. Methods: Utilizing data synthesized from landmark epidemiological reports, functional neuroimaging studies, and guidelines from the National Institute for Health and Care Excellence (NICE) and the American College of Physicians (ACP), the analysis focused on diagnostic triage, routine imaging stewardship, and the neurobiology of pain chronicity. Findings: Findings indicate that the traditional biomedical model drives an "iatrogenic paradox," where over-medicalization and premature imaging induce a nocebo-driven labeling effect, worsening long-term disability. True chronicity is predominantly mediated by central sensitization, nociplastic pathways, and psychosocial yellow flags rather than structural spinal abnormalities. Consequently, clinical assessment must prioritize a "three-bucket" diagnostic triage and validated risk stratification over incidental pathoanatomical findings. Conclusions: Addressing the escalating global burden of CLBP requires a decisive paradigm shift toward a biopsychosocial, stepped-care model. Primary care physicians must act as rigorous gatekeepers against low-value medicalization, instead prioritizing patient education, early reassurance, and active, tailored exercise therapy. Future strategies should emphasize clinical phenotyping and implementation science to effectively bridge the gap between research evidence and routine primary care practice.