The content of the eight principles was discussed early in the Yellow Emperor's Classic of Internal Medicine (206 BC- 25 AD), the bible of traditional Chinese Medicine (TCM). Later on a famous TCM scholar, Zhang Zhongjing (150～219 AD), wrote a book known as Treatise on Cold-induced and Miscellaneous Diseases, that began to use the eight principles for disease diagnosis or identifying disharmony patterns. It was not until the Ming dynasty, that TCM physicians used it regularly in clinical diagnosis.

For example, Zhang San Xi wrote in the book Six Essence of Medicine that: "ancient physicians treated on the basis of eight methods. They were yin, yang, exterior, interior, cold, heat, deficiency (xu) and excess (shi)." Wang Zhizhong, also from the Ming dynasty, said in his book Dong Yuan Xian Sheng Shang Han Zheng Mai that: "they are the eight keys for disease treatment." In the Qing dynasty, Cheng Zhongling further clarified the implications, and claimed that the eight principles are the basic guidelines for examining patients and treating diseases. Today, TCM physicians still use the eight principles to understand the location and nature of pathological changes, the course of disease, and the relationship between pathogenic factors and body’s resistance.