[From result to premise: evolution of the concept of acupuncture-induced deqi and its effect on reinforcing-reducing acupuncture technique].

The concept of deqi in acupuncture was first documented in Huangdi Neijing (The Yellow Emperor's Inner Classics). It is one of the most fundamental concepts in the theory of acupuncture techniques and serves as a representative term for describing acupuncture effect. The relevant judgement and description of it primarily rely on subjective perception and experiences. The response to acupuncture stimulation in the body and its influencing factors are highly complex. Although acupuncture practitioners throughout history have all recognized their importance, their understanding remains inconsistent, leading to inevitable conceptual ambiguity. Based on theoretical analysis of ancient literature, this article argues that the concept of deqi discussed in the acupuncture-related sections of Huangdi Neijing has not yet been formalized into a standardized term. The connotation of deqi has undergone significant transformation, evolving from the "result" of reinforcing-reducing technique to its "premise". The understanding of deqi initiates the development of reinforcing-reducing technique, from "qi communicating with heaven and earth" to "qi beneath needle". The article proposes: understanding deqi should consider the overall reaction of acupuncture and its historical context, elucidating its essential characteristics and practical significance is one of the key issues in constructing the contemporary theoretical framework of acupuncture and preserving its empirical knowledge, and determining deqi and acupuncture efficacy by pulse diagnosis still retain their clinical practical value.