Abstract: Today, we will learn about the differentiation of external pathogenic diseases based on the “Three Transformations”.
Yu Genchu (1734–1799), originally named Zhaoyuan, was from Taoli in Shanyin, Zhejiang (now Shaoxing City). Coming from a family of physicians, Yu inherited medical knowledge early on, extensively reading medical texts from both ancient and modern times, absorbing the strengths of various schools, and particularly delving into Zhang Zhongjing’s theories on febrile diseases, contributing significantly to their development.
He emphasized clinical practice, excelling in treating external febrile diseases with remarkable efficacy, achieving a success rate of ninety percent. Due to his superb medical skills, he was ranked third among his peers, earning him the title of Mr. Yu San.
Yu was known for his extensive knowledge and respectful demeanor, gaining fame in the medical community and earning widespread acclaim over four to five decades during the Qianlong and Jiaqing eras.
As a busy clinician, Yu authored few works, with Tongsu Shanghan Lun being his only surviving masterpiece.
This book has been revised and supplemented by several generations of renowned Zhejiang physicians, including He Xiushan, He Lianchen, Cao Bingzhang, and Xu Rongzhai, from the Qing Dynasty to the early years of the People’s Republic of China, further elaborating and enriching its content, systematically reflecting Yu’s clinical experiences and academic achievements throughout his life.
The entire book centers on febrile diseases, discussing the causes, symptoms, pulse diagnosis, and treatment of all external febrile diseases. It adheres to ancient teachings without being rigid, is thorough yet not superficial, detailed and credible, and practical, earning it the reputation of being a fine work that “draws from the past while adapting to the present”.
By eliminating the boundaries between cold and heat, and merging the studies of febrile and warm diseases, Yu became a pioneer in unifying the study of external pathogenic diseases in Traditional Chinese Medicine (TCM).
Content of the Differentiation of External Pathogenic Diseases Based on the Three Transformations
Based on the clinical characteristics of external pathogenic diseases, Yu utilized the four diagnostic methods to establish the following differentiation of the “Three Transformations”:
1. Fire Transformation
Patients with excessive Yang Qi in their constitution may be affected by the wind, dryness, heat, or cold and dampness, leading to a transformation into heat syndrome due to the interaction of two Yangs.
Transmission to Shaoyang: Shaoyang governs both the exterior and interior; if the pathogen is in the Shaoyang channel, it is more exterior, treated with Chai Hu Zhi Ke Tang (Bupleurum and Bitter Orange Decoction) for harmonizing and relieving the exterior. If the pathogen is in the Shaoyang organ, it is more interior, treated with Hao Qin Qing Dan Tang (Artemisia and Scutellaria Decoction) for harmonizing and clearing.
Transmission to Yangming: If the exterior syndrome has resolved, and the pathogen has entered Yangming, causing interior heat, with diffuse and formless heat filling the Yangming channel, if there is no solid accumulation, it is treated with Xin Liang Xie Re (Spicy Cool Heat Clearing) and supplemented with Bai Hu Tang (White Tiger Decoction); if gastric fluids are depleted and lung fluids are about to be lost, use Ren Shen Bai Hu Tang (Ginseng White Tiger Decoction) with fresh Sheng Di (Rehmannia) and fresh Shi Hu (Dendrobium), pear juice, and Mai Men Dong (Ophiopogon) to nourish fluids and greatly generate lung fluids.
Transmission to Jueyin: Jueyin is the organ of wind and wood, easily transforming heat into wind. If the pathogen transmits to Jueyin, and the heat stagnates, preventing the Jueyin Qi from dispersing, use Qing Gan Da Yu Tang (Liver Clearing and Stagnation Releasing Decoction) or Si Ni San (Frigid Extremities Powder) with Xiang Fu (Cyperus), Huang Lian (Coptis), Sang Ye (Mulberry Leaf), and Yu Jin (Curcuma) to disperse; if the heat pathogen stirs up Jueyin liver fire, use Long Dan Xie Gan Tang (Gentiana Decoction) to greatly drain liver fire; if the heat is extreme and generates wind, causing liver wind to rise, and the pathogen invades the pericardium leading to convulsions and unconsciousness, urgently use Ling Yang Jiao Gou Teng Tang (Antelope Horn and Uncaria Decoction) with Zi Xue Dan (Purple Snow Pill) to extinguish wind and open the orifices.
2. Water Transformation
Patients with insufficient Yang Qi in their constitution may be affected by cold and dampness, leading to a transformation into cold syndrome.
Yangming Water Accumulation: If there is deficiency cold in the stomach, and food and fluids are not separated, there is water accumulation in the interior. If there is still a Taiyang exterior syndrome, use Gui Zhi Ju Pi Tang (Cinnamon Twig and Tangerine Peel Decoction) to first resolve the exterior; if the exterior has resolved, use Xiang Sha Li Zhong Tang (Aromatic Sand Regulating the Middle Decoction) to warm the interior and promote the stomach Qi to transform the water accumulation.
Transmission to Taiyin: Taiyin spleen Qi is inherently deficient, and if affected by cold and dampness, use Huo Xiang Zheng Qi Tang (Agastache Correct Qi Decoction) to aromatically transform dampness.
Transmission to Shaoyin: If kidney Yang is inherently deficient and the Taiyang exterior pathogen has not resolved, it can be treated with Ma Huang Fu Zi Gan Cao Tang (Ephedra, Aconite, and Licorice Decoction) to resolve both.
3. Water and Fire Combined Transformation
Due to the differences in cold and heat of the pathogenic factors and the distinctions in Yin and Yang of the constitution, mixed symptoms of Yin and Yang cold and heat may appear during the course of the disease.
Yu categorized the mixed changes of Yin and Yang cold and heat due to the combined effects of damp-heat pathogenic Qi and the impact of the pathogen on Yin and Yang as Water and Fire Combined Transformation.
Damp-Heat Syndrome: The spleen governs transportation and transformation, and the stomach governs reception; if the spleen and stomach are not harmonious, water and dampness cannot be transformed, leading to stagnation and transformation into heat, or if the external damp-heat pathogen affects the spleen and stomach, it can lead to damp-heat syndrome.
In cases of inherent Qi deficiency, with damp-heat affliction, where Taiyin syndrome is more prevalent than Yangming syndrome, and heat is heavier than dampness, it is advisable to increase or decrease Huang Lian Xie Xin Tang (Coptis Heart-Draining Decoction) for clearing; if dampness obstructs heat and stagnates the Sanjiao, with equal severity of dampness and heat, treat with Sanjiao Fen Xiao (Sanjiao Dispersing Decoction).
Shaoyin and Jueyin Mixed Cold and Heat Syndrome: The hand Shaoyin heart contains the emperor fire, while the foot Shaoyin kidney stores the kidney water; the hand Jueyin pericardium contains gallbladder fire, while the foot Jueyin liver connects with kidney water.
When the pericardium contains gallbladder fire and stirs upward, it manifests as heat wind; when liver Qi contains kidney water, it manifests as cold wind. Fire is hot, and water is cold, hence the symptoms often present as mixed cold and heat.
If water is scorched by fire, and the external pathogen carries fire, leading to Yin deficiency and water fluids unable to ascend, use Huang Lian E Jiao Tang (Coptis and Donkey-hide Gelatin Decoction) to strengthen water and control fire; if fire is obstructed by water, causing internal Yang Qi to stagnate and unable to express outward, use Jia Wei Si Ni San (Modified Frigid Extremities Powder) to disperse stagnation and promote Yang; if there is external cold and internal heat, despite deep cold and deep heat, use Xin Jia Bai Hu Tang (Newly Added White Tiger Decoction); if there is internal cold and external heat, with extreme deficiency of kidney Yang in the lower burner, and floating Yang escaping outward, use Tong Mai Si Ni Tang (Channel Opening Frigid Extremities Decoction) to warm and restore Yang.
Note: Please follow medical advice for specific treatment and medication! This article is excerpted from Ming Yi Yong Ming Fang, edited by Zhang Dong and Song Chunyan, published by People’s Military Medical Publishing House, April 2010. This public account “Xiao Xiangru Channel” is used solely for academic exchange; if there is any infringement, please contact for deletion, and please indicate the source when reprinting.Cover image source: Shetu Network.
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