Endometriosis-associated Pain: Mechanism, Neuroimmune Signature, and Translational Precision Strategies

Endometriosis affects approximately 10% of reproductive-aged women worldwide and is a leading cause of chronic pelvic pain. Despite its high prevalence and substantial socioeconomic burden, the mechanisms underlying endometriosis-associated pain remain incompletely understood, resulting in delayed diagnosis and limited therapeutic durability. Notably, pain severity frequently shows poor correlation with lesion burden, indicating that endometriosis-associated pain extends beyond the presence of endometriotic lesions alone. Accumulating evidence supports a model in which endometriosis-associated pain arises from the convergence of endocrine dysregulation, immune activation, aberrant neuroangiogenesis, and maladaptive neural plasticity, with estrogen dominance and progesterone resistance serving as central upstream drivers of pain biology. Estrogen-dependent inflammation and progesterone resistance establish a permissive microenvironment that promotes immune dysfunction, neurotrophic signaling, and nociceptor sensitization. These peripheral processes drive sustained afferent input to the central nervous system, leading to peripheral, central, and cross-organ sensitization that can perpetuate pain independently of lesion activity. In this review, we synthesize current evidence across the clinical spectrum of pain, mechanistic pathways, and therapeutic approaches in endometriosis. We integrate insights from inflammatory and immune pathways, neuroimmune crosstalk, hormonal regulation, and sensitization processes, emphasizing progesterone resistance and estrogen-mediated signaling as central modulators. Advances from preclinical models and emerging multi-omics technologies are highlighted to define pain signatures that transcend lesion-based classification. Finally, we discuss emerging therapeutic strategies targeting neuroimmune and endocrine pathways and propose a precision medicine framework that incorporates mechanistic biomarkers, translational models, and pain-specific clinical endpoints to improve stratification, reduce ineffective interventions, and achieve individualized pain relief for women with endometriosis.