ABSTRACT
From the perspective of academic history, the background and evolution of "Fenglong (ST 40) for phlegm" were systematically summarized. As a result, it was found that in the early period, Fenglong (ST 40) was used for "tangible phlegm" of respiratory tract, but in the later generations, due to the comprehensive effects of various factors, the phlegm treated by Fenglong (ST 40) was generalized. In modern clinical practice of acupuncture and moxibustion, Fenglong (ST 40) is widely used for phlegm-related diseases. In addition, the knowledge content represented by "Fenglong (ST 40) for phlegm" showed evolution and change in academic heritage of previous dynasties. It is necessary for modern acupuncture researchers to systematically sort out, test and discriminate the habitual knowledge in combination with the background of traditional Chinese medicine, so as to promote the contemporary inheritance and application of traditional acupuncture theory and knowledge.