Abstract：The phrase "when yang overwhelms yin，it is termed abnormal sweating" originates from Su Wen·Yin Yang Bie Lun （Chapter Ⅶ of Basic Questions）. Its meaning has been interpreted in various ways throughout history； however， most interpretations tend to explain the physiological mechanism of sweat secretion， which does not fully align with the original context of pulse diagnosis and disease differentiation. By systematically reviewing the discourse on "sweating" in Huang Di Nei Jing （The Yellow Emperor's Inner Classic），and employing philological，contextual，and traditional Chinese medicine theoretical methods， this paper examines and reinterprets the classical text. The study finds that the character "jia" in pre-Qin and Han dynasty texts often conveys the meanings of "to overwhelm" or "to press upon." Moreover， all seven instances of the sentence pattern “ …wei zhi… ” in Su Wen·Yin Yang Bie Lun refer to specific diseases or particular physiological states. Therefore，"sweating" in "when yang overwhelms yin，it is termed abnormal sweating" should be understood as pathological sweating requiring diagnosis. Accordingly， this statement should carry a dual connotation：it is both a diagnostic element within the pulse diagnosis system of Su Wen·Yin Yang Bie Lun and a highly generalized core pathogenesis of pathological sweating. This paper aims to return to the original diagnostic meaning of the classical text，clarify interpretative misunderstandings in later commentary，and reveal the theoretical path by which it ascended from a specific diagnostic method to a core pathogenesis， thereby providing a classical-text-derived theoretical approach for the clinical differentiation and analysis of sweating disorders.