Endometrial dysfunction represents a central pathological factor underlying recurrent implantation failure and infertility. This review provides a comprehensive synthesis of the physiological basis of endometrial function, the pathological factors compromising its integrity, and the impact of these abnormalities on embryo implantation. Key pathogenic drivers, including cellular senescence, chronic inflammation, iatrogenic injury, endometriosis, and microbiome dysbiosis, converge on common mechan