阴平阳秘，是《黄帝内经》对人体最佳生命活动状态的高度概括。阴平阳秘，即阴与阳在保持各自功用和特性的情况下，通过相互作用所达到的整体协调状态，是对生命活动中各种功能之间复杂关系及有机联系的抽象概括。正常人，其"阴平阳秘"的生理状态，可综合体现在经络调畅、九候若一、脉应四时、寒温相守、形肉相称、气血和调、脏腑相协等方面。倘若阴阳失调，上述生理过程必然失常，一旦阴阳之间失去相互维系的关系，"阴平阳秘"即告瓦解，生命就会终止。 ( Relative equilibrium of yin-yang is the high generalization to the best human life situation in Yellow Emperor's Canon of Medicine. Relative equilibrium of yin-yang refers to the overall coordinated condition of the interaction of yin and yang as they both keep their own function and features and it has been the abstract generalization to the complicated relation and organic connection of various functions in vital movement. Such physical condition of normal people could be shown in the following phenomena: meridian is adjusted to be smooth, nine divisions are the same, the pulse agrees with four seasons, cold and warmth meet the balance, the proportion of meat is proper, qi and blood are coordinated, zang and fu viscera are interconnected with each other. If the yin and yang are imbalanced, the above physical process must be abnormal and once the yin and yang could not keep their inter-maintaining relation, relative equilibrium of yin-yang would collapse and the life would come to the end. )