This paper elucidates the connotation and extension of the concept of"impending illness"from the per-spective of logic.The connotation of impending illness refers to the intermediate state between health(not yet sick)and disease(already sick),characterized by the initial instability of yin and yang or a low-level balance of yin and yang as its internal mechanism,and mild dysfunctions in physiological,psychological,and social functions as its manifestations.The extension of impending illness includes latent disease status and pre-disease status.By adopting a creative hermeneutic approach to explore the deep-seated connotations of impending illness,this paper systematically analyzes the concept of impending illness from five levels:the existential level,the intentional level,the implicational level,the situational level,and the necessitational level,arguing that impending illness represents the unity of ambi-guity and precision,the deviation of the human body system from homeostasis within a certain range,and an impor-tant component of the improvement of the traditional Chinese medicine health management system.Thoroughly expli-cating and clarifying the concept of"impending illness"can provide theoretical references for the study of transitional states between health and disease and the improvement of the traditional Chinese medicine health management system.