中药“双向调节”现象作为中医特色效应之一，体现了“以平为期”的治疗宗旨，然而其背后的动态方向选择机制难以通过现代药理学“成分-靶点”的静态分析范式或传统“证-效”关系的经验归纳中得到充分阐释。针对这一理论瓶颈，立足中医本体思维，引入并深化“势”的理论范畴，构建一个能够有机贯通“机体状态-药物特性-效应方向”的动态解释框架。提出“察势以明机，顺势以为调”的基本思路，创新性地界定了“病势”“趋和之势”与“药势”3个核心范畴，并以“因势利导”为基础构建了“病势-趋和之势-药势”三元动态响应模型。该模型将中药双向调节的本质重新界定：在特定“病势”背景下，机体固有的自我平衡趋势，即“趋和之势”被激活且缺乏恢复平衡的条件，而具有恒定趋向的“药势”作为一种外源性干预工具，通过精准协同与激发“趋和之势”，从而引导系统从不同失衡方向回归动态平衡的过程。进一步从“病势-趋和之势-药势”角度解析了单味药如大黄和刺蒺藜、柴胡-黄芩药对、桂枝汤复方等中药的双向调节机制。并将“势”学机制延伸至临床辨治层面，旨在为中医临床从“辨证”向“辨势察机”、从“选方”向“精准择势”的思维深化提供新的视角与理论支点，以期推动“势”学中医理论的现代诠释发展。

The phenomenon of “bidirectional regulation” in traditional Chinese medicine (TCM), as one of its characteristic therapeutic effects, embodies the treatment principle of “achieving equilibrium as the therapeutic goal”. However, the underlying dynamic mechanism governing the selection of regulatory direction cannot be adequately explained through the static “component-target” paradigm of modern pharmacology or the empirical induction of traditional “pattern-effect” relationships. To address this theoretical bottleneck, this study, grounded in the intrinsic logic of TCM thinking, introduces and elaborates on the theoretical concept of “dynamic tendency”, constructing a dynamic explanatory framework that organically integrates “body state”, “medicinal properties”, and “effect direction”. This study proposes the basic approach of “discerning the dynamic tendency to clarify the mechanism, and following the dynamic tendency to regulate accordingly”. It innovatively defines three core categories—“disease tendency”, “tendency towards homeostasis”, and “herbal tendency” and, based on the principle of “guiding according to the tendency”, constructs a ternary dynamic response model of “disease tendency-tendency towards homeostasis-herbal tendency”. This model redefines the essence of bidirectional regulation in TCM as follows: within the context of a specific “disease tendency”, the body's inherent self-balancing trend—the “homeostatic tendency” is activated yet lacks the conditions to restore equilibrium. The “herbal tendency”, as an exogenous intervention with a consistent directional property, precisely coordinates with and stimulates this “homeostatic tendency”, thereby guiding the system back to dynamic balance from various states of deviation. Furthermore, the paper analyzes the bidirectional regulatory mechanisms of single herbs (such as Dahuang-Cijili), herb pairs (such as Chaihu-Huangqin), and compound formulas (such as Guizhi Tang) through the lens of the “disease tendency-homeostatic tendency-herbal tendency” framework. Extending the “tendency” theory to the level of clinical diagnosis and treatment, this study aims to provide a new perspective and theoretical foundation for deepening TCM clinical thinking from “pattern differentiation” toward “tendency differentiation and mechanism discernment”, and from “formula selection” toward “precise tendency alignment”. This is intended to promote the modern interpretation and development of “tendency-based” theory in TCM.

R284.1

四川省自然科学基金重点项目（25ZDIZX025）；国家自然科学基金面上项目（82574995）；第六批四川省名中医传承工作室建设项目——四川省名中医高泓传承工作室（川中医药办发 [2023] 36号）；成都中医药大学附属医院省重点实验室专项基金（23SZ03，23SZ05，23SZ06）