Library

Liu Hejian stated: "Ke" (cough with sound but no phlegm) refers to the impairment of Lung Qi resulting in a lack of clarity; "Sou" (phlegm production without sound) refers to Spleen dampness stirring up and generating phlegm; "Ke Sou" (cough with both sound and phlegm) occurs due to injury to Lung Qi and agitation by Spleen dampness, where coughing leads to phlegm production. The so-called Spleen dampness arises from dampness injured in autumn, accumulating in the Spleen. Thus, the classics state: "Injury to dampness in autumn leads to Ke Sou in winter." Generally, the qi of early autumn should be clear and肃 (descending/clearing); if this is disturbed, the qi must rush upward causing Ke Sou, and severely, it moves dampness to generate phlegm. If dampness resides in the Liver channel, it is called Wind Phlegm; if in the Heart channel, Heat Phlegm; if in the Spleen channel, Damp Phlegm; if in the Kidney channel, Cold Phlegm. Treatment should follow the specific syndrome. For dry cough without phlegm, one should moisten the Lung with acrid-sweet substances, such as Honey-fried Ginger Decoction or Honey-fried Tangerine Peel Decoction. For cough accompanied by phlegm, treating phlegm should be prioritized. Treating phlegm requires regulating Qi as the main principle; thus, using Arisaema Rhizoma (Nanxing) and Pinellia Tuber (Banxia) eliminates phlegm, and Ke Sou heals spontaneously; using Aurantium Fructus (Zhike) and Citrus Reticulatae Pericarpium (Chenpi) benefits Qi flow, and phlegm descends naturally. If phlegm is present but the patient can eat, Da Cheng Qi Tang (Great Conveyer Qi Decoction) should be used for mild purgation; if phlegm is present but the patient cannot eat, Nong Po Tang (Thick Magnolia Bark Decoction) should be used for dredging and guiding. This is the general principle of treatment.

I observe that Liu Hejian's theory advocates treating Sou first by addressing phlegm, primarily using Arisaema Rhizoma and Pinellia Tuber, which seems to grasp the method for treating Sou. His intent implies that Sou must be caused by phlegm, so eliminating phlegm cures Sou. However, this reasoning is not entirely correct. Generally, external contraction-induced Sou is necessarily due to Wind-Cold. When Wind-Cold invades the Lung, Lung Qi becomes unclear, triggering cough; prolonged cough then stirs phlegm. The root of Wind-Phlegm Sou lies in external contraction, not that external contraction originates from phlegm. Similarly, internal injury-induced Sou is necessarily due to Yin Deficiency. Yin Deficiency leads to dried fluids and withered Metal (Lung), triggering cough; Spleen deficiency and Kidney failure generate phlegm. The root of Yin-Deficient Phlegm Sou lies in internal injury, not that internal injury originates from phlegm. To say that treating Sou requires first treating phlegm—is this seeking the root? Yet, for treating external contraction-induced Sou, Er Chen Tang (Two-Aged Decoction) and similar formulas are indeed most effective. Why is this? Because Arisaema Rhizoma, Pinellia Tuber, Fresh Ginger, Citrus Reticulatae Pericarpium, and Aurantium Fructus all have Acrid flavors. Acrid enters the Lung, and Acrid disperses Cold. Once Cold pathogens are dispersed, Phlegm-Sou heals spontaneously. This is truly treating the root, not merely treating phlegm. Conversely, for internal injury Yin-Deficient Sou, Acrid-Dry substances are strictly contraindicated; how can these herbs be lightly used? The classics state: "The Lung desires Acrid; use Acrid to drain it," which applies to Lung Excess patterns suitable for Acrid. It also states: "Acrid moves Qi; do not consume much Acrid when Qi is diseased," which applies to Lung Deficiency patterns contraindicating Acrid. The principles regarding the suitability of flavors and properties are applied so exquisitely in the Huangdi Neijing (Yellow Emperor's Inner Canon). Why did Liu Hejian fail to examine this, claiming that Arisaema Rhizoma and Pinellia Tuber only treat phlegm? Does treating the branch of phlegm truly cure the root of Sou?