IV. TCM Syndrome Differentiation and Prescription Analysis

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: "The causes of asthma lie in the accumulation and stagnation of phlegm-dampness, which forms a pathological nest and lies dormant within the body. Occasionally, when the seven emotions are disturbed or dietary habits are improper, or when external seasonal wind-cold pathogens invade and constrict the skin and muscles, asthma symptoms manifest." Zhu Danxi first coined the term "asthma" and elucidated that the pathogenesis is primarily due to phlegm, proposing the treatment principle of "prioritizing tonifying vital energy before an attack and urgently expelling pathogenic factors once an attack occurs."

Professor Pei Zhengxue believes that the onset of asthma is often due to dysfunction of the lung, spleen, and kidney, leading to internal accumulation of water-dampness as phlegm-stasis, which lies hidden in the lungs and becomes the underlying "root cause" of asthma. When external pathogenic factors trigger it, the phlegm-stasis obstructs the airways, resulting in asthma attacks. The primary pathological factor is phlegm; its formation is attributed to the lung's inability to disperse body fluids, the spleen's failure to transport nutritive essence, and the kidney's inability to vaporize water, causing body fluids to condense into phlegm-stasis that lurks in the lungs as the "root cause" of the disease. Subsequently, various triggers such as sudden climate changes, improper diet, emotional disturbances, and overexertion can all precipitate an attack. These triggers are often interrelated, with climate being the most significant. During an attack, the "latent phlegm" is triggered by external stimuli, rising with the qi, while the qi, obstructed by phlegm, collides and binds together, blocking the airways and narrowing the lung passages, impeding smooth airflow and disrupting the normal ascending and descending movement of lung qi, thereby causing wheezing and shortness of breath. Phlegm obstruction leads to qi closure, characterized mainly by excess pathogenic factors and difficulty in exhaling, with patients feeling relieved only upon exhalation. If the etiology is cold, and the individual has inherent yang deficiency, the phlegm transforms into cold phlegm, resulting in cold asthma; if the etiology is heat, and the individual has inherent yang excess, the phlegm transforms into hot phlegm, leading to heat asthma; or, when "internal phlegm-heat accumulates while external wind-cold constrains it," a pattern of cold enclosing heat may appear. If the condition recurs repeatedly over a long period, cold phlegm damages the yang of the spleen and kidneys, while hot phlegm depletes the yin of the lungs and kidneys, potentially shifting from excess to deficiency. In such cases, during remission, patients may exhibit signs of weakness in the lung, spleen, and kidney qi. The lung's deficiency prevents it from governing qi, leading to stagnation of phlegm and impaired descending function, coupled with weakened defensive qi, making them more susceptible to external pathogenic invasions. The spleen's inability to transform food and drink into nutritive essence and transport it upward to nourish the lungs results in dampness accumulation and phlegm formation, which then accumulates in the lungs, affecting the lung's ascending and descending qi. The kidney's deficiency in essence and qi leads to inadequate containment, causing yang deficiency and water overflow into phlegm, or yin deficiency and dryness-induced phlegm, both of which ascend to the lungs, disrupting the lung's ability to regulate qi flow. Due to the mutual influence among these three organs, combined conditions may arise, presenting as qi and yang deficiency in the lung, spleen, and kidney, or as yin deficiency in the lung and kidney. During the intermission phase, patients may experience shortness of breath and fatigue, often with mild asthma symptoms that are difficult to completely eliminate. Once a severe attack occurs, it tends to persist without relief, with complex interactions between excess pathogenic factors and deficiency of vital energy, resulting in dual deficiency of the lung and kidney and recurrent phlegm stasis. In severe cases, since the lungs cannot properly regulate the circulation of heart blood, and the life gate fire cannot ascend to nourish the heart, the heart's yang is also affected, potentially leading to the critical condition of "asthma-related collapse."

IV. TCM Syndrome Differentiation and Prescription Analysis

(1) Attack Phase

1. Cold Asthma Symptoms: Rapid breathing, wheezing in the throat, chest and diaphragm feeling full and blocked, coughing is not severe, sputum is scanty and difficult to expectorate, complexion is dull with a bluish tinge, no thirst or preference for warm drinks, prone to flare-ups in cold weather or after exposure to cold, aversion to cold, white and slippery tongue coating, pulse is string-like and tight or floating and tight. Treatment Principle: Warm the lungs and dispel cold, transform phlegm and relieve asthma. Prescription: Shegan Mahuang Decoction, modified Xiaochenglong Decoction. Shegan 10g, Mahuang 10g, Dried Ginger 6g, Xixin 3g, Banxia 6g, Zi 10g, Kuandonghua 10g, Gancao 6g, Wuweizi 6g, Dazao 4 pieces, Xingren 10g, Suzi 10g, Baiqian 10g, Jupi 6g.
2. Heat Asthma Symptoms: Coughing and wheezing with coarse, roaring sounds, wheezing in the throat like a roar, distension and fullness in the chest and sides, paroxysmal coughing, sticky, thick, and turbid sputum that is difficult to expel, yellow or white in color, restlessness and irritability, sweating, flushed face, bitter taste in the mouth, thirst and preference for drinks, red tongue body, greasy yellow tongue coating, slippery and rapid pulse. Treatment Principle: Clear heat and diffuse lung qi, transform phlegm and stabilize asthma. Prescription: Dingchuan Decoction, Maxing Shigan Decoction, modified Sanzi Yangqin Decoction. Mahuang 10g, Huangqin 10g, Sangbaipi 10g, Xingren 10g, Banxia 6g, Kuandonghua 10g, Suzi 10g, Baiguo 10g, Gancao 10g, Shigao 30g, Guizhi 10g, Shengjiang 10g, Laizi 10g, Zunzi 10g, Yuxingcao 20g, Zhimu 20g. (2) Remission Phase
3. Lung and Spleen Deficiency