Brief history:
Eight programs originated from Neijing in the Warring States Period, and put forward the concepts of cold and heat and excess and deficiency. In Treatise on Febrile Diseases in Han Dynasty, Zhang Zhongjing summarized and distinguished diseases and syndromes from four aspects: yin and yang, exterior and interior, cold and heat, and excess and deficiency. Wang Zhi in Ming Dynasty
Cold and heat in the exterior and interior of deficiency and excess yin and yang are called "eight characters for treating diseases"; Zhang Jingyue clearly put forward the theory that Yin and Yang are "two cardinal principles" and exterior, cold and heat, and excess and deficiency are "six changes". In the Qing Dynasty, Cheng Zhongling further elaborated the meaning of the eight cardinal principles, and proposed that the examination and treatment of syndromes were nothing more than cold and heat, excess and deficiency, exterior and interior, and yin and yang. Abstract of Modern Medicine (1897) put forward the word "Eight Classics". After 1949, with the establishment of the academic status of syndrome differentiation and treatment, the eight programs are the core position and important works in syndrome differentiation and treatment.
The use is fully affirmed.