RESUMEN
“Deficiency cause， cold accumulation， and qi stagnation” originates from Essentials from the Golden Cabinet （《金匮要略》）， which is a guiding principle for the pathogenesis of women's diseases， pioneering the differentiation and treatment of women's diseases based on patterns， and having a profound influence on future generations. Following the classical principles and simplifying the complexities， this paper explored the pathogenesis and mechanism of polycystic ovary syndrome （PCOS） from the perspective of “deficiency cause， cold accumulation， and qi stagnation”， and believed that depletion of essence and blood， long-term accumulation of internal cold， and qi constraint and blood stasis are the causes of PCOS， with depletion of essence and blood， and lack of nourishment of zang-fu （脏腑） organs as the root， and cold pathogen invasion， qi constraint and blood stasis as the branch. The main treatment principle is “treating deficiency with supplementation”， and dispelling pathogen while reinforcing healthy qi， along with “treatment of cold by warming” and “treatment of stagnation by dispersing”. This is of great significance for the treatment of polycystic ovary syndrome. Clinically， these methods can be used flexibly to guide treatment and formula selection for PCOS， with the goal of harmonizing qi and blood and regulating menstruation.