Insomnia Pathogenesis and Multidimensional Mechanisms of Acupuncture: A Narrative Review.

Objective: Insomnia is a common sleep disorder marked by difficulties in sleep initiation, maintenance, and daytime performance. Pharmacological treatments offer short-term relief but are limited by tolerance, dependence, and adverse effects. This review aims to evaluate recent advances in acupuncture for insomnia, with emphasis on clinical efficacy and underlying mechanisms. Methods: This narrative review was conducted through a structured literature search of PubMed, Web of Science, and CNKI databases covering studies published from January 2020 to December 2025. The search combined keywords including "insomnia", "acupuncture", "mechanism", "autonomic nervous system", "inflammation", and "HPA axis". Both clinical and preclinical studies published in English or Chinese were considered. Studies were screened based on relevance to acupuncture interventions for insomnia and mechanistic outcomes. Although a formal systematic review protocol was not applied, emphasis was placed on representative and high-quality evidence to summarize key mechanistic pathways. Results: Evidence suggests that acupuncture improves subjective sleep quality, alleviates hyperarousal, reduces systemic inflammation, and promotes neuroimmune balance through multidimensional mechanisms. However, limitations remain, including small sample sizes, methodological heterogeneity, inadequate blinding, and insufficient mechanistic exploration. Conclusion: Acupuncture is a promising integrative intervention for insomnia with both symptomatic and mechanistic benefits. Future studies should prioritize large-scale, multicenter randomized controlled trials and standardized protocols, while incorporating multi-omics, neuroimaging, and precision medicine approaches. Interdisciplinary collaboration may advance acupuncture from empirical therapy to precision medicine, providing new opportunities for comprehensive insomnia management.