咳谓无痰而有声。嗽是有痰而有声。虽分六腑五脏之殊。而其要皆主于肺。盖肺为清虚之府。一物不
容。毫毛必咳。又肺为娇脏。畏热畏寒。火刑金故嗽。水冷金寒亦嗽。故咳嗽者。必责之肺。而治之之法。不
在于肺。而在于脾。不专在脾。而反归重于肾。盖脾者。肺之母。肾者。肺之子。故虚则补其母。虚则补其子也。
如外感风寒而咳嗽者。今人率以麻黄枳壳紫苏之类。发散表邪。谓从表而入者。自表而出。如果系形气病
气俱实者。一汗而愈。若形气病气稍虚者。宜以补脾为主。而佐以解表之药。何以故。盖肺主皮毛。惟其虚也。
故凑理不密。风邪易以入之。若肺不虚。邪何从而入耶。古人所以制参苏饮中必有参。桂枝汤中有芍药甘草。解
表中兼实脾也。脾实则肺金有养。皮毛有卫。已入之邪易以出。后来之邪。无自而入矣。若专以解表。则肺气
益虚。腠理益疏。外邪乘间而来者。何时而已耶。须以人参黄 甘草以补脾。兼桂枝以驱邪。此予谓不治肺
而治脾。虚则补其母之义也。
仁斋直指云。肺出气也。肾纳气也。肺为气之主。肾为气之本。凡咳嗽暴重。动引百骸。自觉气从脐下逆
奔而上者。此肾虚不能收气归元。当以地黄丸安肾丸主之。母徒从事于肺。此虚则补子之义也。余又有说焉。
五行之间。惟肺肾二藏。母盛而子宫受邪。何则。肺主气。肺有热。则气得热而上蒸。不能下生于
肾。而肾受邪矣。肾既受邪。则肺益病。此又何也。盖母藏子宫。子隐母胎。凡人肺金之气。夜卧则归藏于
肾水之中。今因肺受心火之邪。欲下避水中。而肾水干枯有火。无可容之地。于是复上而病矣。
有火烁肺金而咳嗽者。宜清金降火。今之医书中。论清金降火者。以黄芩天麦冬桑白皮清肺金。以黄
连降心火。石膏降胃火。以四物黄柏知母降阴火。谓枳半燥泄伤阴。易用贝母栝蒌竹沥枇杷叶以润肺而化痰。
以上治法。岂不平正通达耶。殊不知清金降火之理。似是而实非。补北方。正所以泻南方也。滋
其阴。即所以降火也。独不观启玄子壮水之主。以制阳光乎。予相火论。及滋阴降火论中。已详言黄柏知母
之不宜用。与夫寒凉诸药之害矣。予又有说焉。王节斋云。凡酒色过度。损伤肺肾真阴者。不可服参 。
服之过多则死。盖恐阳旺而阴消也。自此说行。而世之治阴虚咳嗽者。视参 如砒毒。以黄柏知母为灵
丹。使患此证而服此药者。百无一生。良可悲也。有能寡欲而不服药者。反可绵延得活。可见非病不可治。
乃治病之不如法也。盖病本起于房劳太过。亏损真阴。阴虚而火上。火上而刑金故咳。咳则金不能不伤矣。
予先以壮水之主之药。如六味地黄之类。补其真阴。使水升而火降。随即以参 救肺之品。以补肾
之母。使金水相生而病易愈矣。世之用寒凉者。肤浅庸工。固不必齿。间有知用参 者。不知先壮水以镇火。
而遽投参 以补阳。反使阳火愈旺。而金益受伤。岂药之罪哉。此所谓不识先后着者也。
有脾胃先虚。土虚不能制水。水泛为痰。子来乘母而嗽者矣。又有初虽起于心火刑金。因误服寒凉。以致
脾土受伤。肺益虚而嗽者。乃火位之下。水气承之。子来救母。肾水复火之仇。寒水挟木势而上侵于肺胃。水
冷金寒故嗽。前病未除。新病愈甚。粗工不达此义。尚谓痰火难除。寒凉倍进。岂不殆哉。斯时也。须用六君
子汤加炮姜。以补脾肺。八味丸以朴土母。而引水归原。此等治咳嗽之法。幸同志者加之意焉。
金匮云。咳而上气。喉中水鸡声、射干麻黄汤主之。此论外感。
有嗽而声哑者。盖金实不鸣。金破亦不鸣。实则清之。破则补之。皆治肺之事也。又须知少阴之络入肺
中。循喉咙。挟舌本。肺为之标。本虚则标弱。故声乱咽嘶。舌萎声不能前。出仲景伤寒书。
一男子年五十余岁。病伤寒咳嗽。喉中声如 。与独参汤。一服而 声除。至二三服而咳嗽亦渐退。服二
三斤病始全愈。（此阳虚之案。）
衍义云。有暴嗽服诸药不效。或教之进生料鹿茸丸大菟丝子丸方愈。有本有标。却不可以其暴嗽。而疑
骤补之非。所以易愈者。亦觉之早故也。（此阴虚之案。）
有一等干咳嗽者。丹溪云。干咳嗽极难治。此系火郁之证。乃痰郁其火。邪在中。用逍遥散以开之。下
用补阴之剂而愈。
Cough (Ke, 咳嗽) refers to a condition with sound but no phlegm. Sao (Sao, 嗽) refers to a condition with both phlegm and sound. Although there are distinctions among the Six Fu Organs and Five Zang Organs, the key lies in the Lung (Fei, 肺). The Lung is a clear and empty organ that tolerates no foreign matter; even slight pathogenic invasion of the hair and skin will cause coughing. Furthermore, the Lung is a delicate organ, fearing both heat and cold. Fire pathogen punishing Metal causes Sao, and cold water freezing Metal also causes Sao. Therefore, cough must be attributed to the Lung, yet the treatment method does not lie in treating the Lung directly, but rather in treating the Spleen (Pi, 脾); it is not solely focused on the Spleen, but instead places greater emphasis on treating the Kidney (Shen, 肾). This is because the Spleen is the Mother of the Lung, and the Kidney is the Child of the Lung. Thus, for deficiency, one tonifies the Mother (Spleen), and for deficiency, one also tonifies the Child (Kidney).
If cough is caused by external contraction of Wind-Cold (Fenghan, 风寒), people nowadays generally use herbs such as Ephedrae Herba (Mahuang, 麻黄), Aurantii Fructus Immaturus (Zhike, 枳壳), and Perillae Folium (Zisu, 紫苏) to disperse exterior pathogens, arguing that since the pathogen entered from the exterior, it should exit via the exterior. If the patient’s constitution and pathogenic qi are both excess, a single sweating treatment can lead to recovery. However, if the constitution or pathogenic qi is slightly deficient, the primary approach should be tonifying the Spleen, assisted by exterior-resolving medicines. Why? Because the Lung governs the skin and hair. It is precisely due to Lung deficiency that the interstices (Couli, 腠理) are not tight, allowing Wind pathogen to easily enter. If the Lung were not deficient, from where would the pathogen enter? This is why ancient physicians included Ginseng Radix et Rhizoma (Renshen, 人参) in Shen Su Yin (Ginseng and Perilla Decoction) and included Paeoniae Radix Alba (Baishao, 白芍) and Glycyrrhizae Radix et Rhizoma (Gancao, 甘草) in Guizhi Tang (Cinnamon Twig Decoction), thereby strengthening the Spleen while resolving the exterior. When the Spleen is solid, Lung Metal is nourished, and the skin and hair have protective Wei Qi (Defensive Qi). Pathogens already inside are easily expelled, and new pathogens cannot enter. If one exclusively uses exterior-resolving methods, Lung Qi becomes more deficient, and the interstices become looser, allowing external pathogens to take advantage of the gap indefinitely. One must use Ginseng Radix et Rhizoma (Renshen, 人参), Astragali Radix (Huangqi, 黄芪), and Glycyrrhizae Radix et Rhizoma (Gancao, 甘草) to tonify the Spleen, combined with Cinnamon Twig (Guizhi, 桂枝) to drive out pathogens. This is what I mean by treating the Spleen instead of the Lung, following the principle of "tonifying the Mother when deficient."
Ren Zhai stated in *Zhizhi Fang* (Directing Guide): The Lung exhales Qi, and the Kidney grasps Qi. The Lung is the master of Qi, and the Kidney is the root of Qi. Whenever cough suddenly worsens, affecting the whole body, and the patient feels Qi rushing upward from below the navel, this indicates Kidney deficiency failing to gather Qi back to its origin. One should treat with Dihuang Wan (Rehmannia Pill) or Anshen Wan (Calming Kidney Pill). Do not merely focus on the Lung; this illustrates the principle of "tonifying the Child when deficient." I have further remarks. Among the Five Elements, only the Lung and Kidney exhibit a scenario where the Mother is excessive and the Child suffers from pathogenic influence. Why? The Lung governs Qi. If the Lung has Heat, Qi rises and steams upward due to heat, failing to descend to nourish the Kidney, thus the Kidney suffers from pathogenic influence. Once the Kidney is affected, the Lung becomes even sicker. Why is this? Because the offspring of the Mother organ resides within it, and the hidden aspect of the Child organ is within the Mother's womb. Normally, the Qi of Lung Metal returns to reside within Kidney Water during sleep at night. Now, because the Lung is invaded by Heart Fire pathogen, it seeks to descend into the Water for refuge, but Kidney Water is dry and contains Fire, leaving no place for containment. Consequently, the Qi rebels upward and causes disease.
For cough caused by Fire scorching Lung Metal, clearing Metal and descending Fire is appropriate. Current medical texts discussing clearing Metal and descending Fire use Scutellariae Radix (Huangqin, 黄芩), Asparagi Tuber (Tianmendong, 天冬), Ophiopogonis Tuber (Mendong, 麦冬), and Morus Cortex (Sangbaipi, 桑白皮) to clear Lung Metal; Coptidis Rhizoma (Huanglian, 黄连) to descend Heart Fire; Gypsum Fibrosum (Shigao, 石膏) to descend Stomach Fire; and Siwu Tang (Four Substances Decoction) combined with Phellodendri Cortex (Huangbai, 黄柏) and Anemarrhenae Rhizoma (Zhimu, 知母) to descend Yin Fire. They argue that Atractylodis Rhizoma (Zhi, 枳) and Pinelliae Tuber (Banxia, 半夏) are drying and draining, damaging Yin, so they substitute with Fritillariae Bulbus (Beimu, 贝母), Trichosanthis Fructus (Gualou, 瓜蒌), Bamboo Sap (Zhuli, 竹沥), and Loquat Leaf (Pipaye, 枇杷叶) to moisten the Lung and resolve phlegm. Are these treatment methods not balanced and thorough? Little do they know that the logic of clearing Metal and descending Fire seems correct but is actually wrong. Tonifying the North (Kidney Water) is precisely how one drains the South (Heart Fire). Nourishing Yin is itself the method to descend Fire. Have they not observed Wang Bing (Qixuanzi) stating: "Strengthen the Master of Water to control the Sunlight"? In my *Lun Xianghuo* (Discourse on Ministerial Fire) and *Ziyin Jianghuo Lun* (Discourse on Nourishing Yin and Descending Fire), I have already detailed why Huangbai and Zhimu should not be used and the harms of various cold-cooling medicines. I have further remarks. Wang Jiezhai said: For those whose Lung and Kidney True Yin are damaged by excessive alcohol and sexual indulgence, Renshen and Huangqi should not be taken. Taking too much leads to death, presumably fearing that Yang prosperity will consume Yin. Since this saying spread, practitioners treating Yin-deficiency cough regard Renshen and Huangqi as arsenic poison and view Huangbai and Zhimu as spiritual elixirs. Patients with this condition taking these medicines rarely survive, which is truly tragic. Those who can restrain desires and avoid medicine反而 recover. This shows the disease is not incurable, but the treatment method is improper. The disease originates from excessive sexual labor, depleting True Yin. Yin deficiency leads to Fire flaming upward; Fire flaming upward punishes Lung Metal, causing cough, which inevitably injures Lung Metal. I first use medicines to strengthen the Master of Water, such as Liuwei Dihuang Wan (Six-Ingredient Rehmannia Pill), to tonify True Yin, raising Water and descending Fire. Then, I immediately use Renshen and Huangqi to rescue the Lung and tonify the Mother of the Kidney, promoting Metal-Water mutual generation for easier recovery. Practitioners using cold-cooling medicines are superficial and mediocre, unworthy of mention. Occasionally, some know to use Renshen and Huangqi but fail to first strengthen Water to suppress Fire, rashly administering them to tonify Yang. This反而 makes Yang Fire more prosperous and Lung Metal more injured. Is it the fault of the medicine? This is called failing to recognize the sequence of steps.
There are cases where the Spleen and Stomach are initially deficient, Earth fails to control Water, Water overflows transforming into Phlegm, and the Child organ (Lung) attacks the Mother organ (Spleen), causing cough. There are also cases initially starting with Heart Fire punishing Metal, but due to mistaken use of cold-cooling medicines, Spleen Earth is injured, making the Lung more deficient and causing cough. Here, below the position of Fire, Water Qi takes over. The Child organ (Kidney) comes to save the Mother organ (Lung), but Kidney Water aids the enemy of Fire. Cold Water, carrying the momentum of Wood, invades the Lung and Stomach. Cold water freezing Metal causes cough. The previous illness remains, and the new illness worsens. Crude practitioners do not understand this meaning, still believing Phlegm-Fire is hard to remove, and doubling the dose of cold-cooling medicines. Is this not dangerous? At this time, one must use Liujunzi Tang (Six Gentlemen Decoction) with roasted Ginger (Paojiang, 炮姜) to tonify Spleen and Lung, and Bawei Wan (Eight-Ingredient Pill, i.e., Jin Gui Shenqi Wan) to thicken Earth (Mother) and guide Water back to its origin. May colleagues pay attention to these methods for treating cough.
*Jin Gui Yao Lue* states: Cough with rebellious Qi and a sound in the throat like a water frog is treated with Shegan Mahuang Tang (Belamcanda and Ephedra Decoction). This discusses external contraction.
For cough with hoarseness, it is said that when Metal is solid, it does not ring; when Metal is broken (deficient), it also does not ring. Excess is cleared, deficiency is tonified; both are matters of treating the Lung. One must also know that the collateral of the Shaoyin meridian enters the Lung, follows the throat, and flanks the base of the tongue. The Lung is the branch (Biao, 标); if the root (Ben, 本) is deficient, the branch is weak. Thus, voice is chaotic, throat is hoarse, tongue is flaccid, and voice cannot project. This comes from Zhang Zhongjing's *Shanghan Lun* (Treatise on Cold Damage).
A man over fifty years old suffered from Shanghan cough, with a sawing sound in his throat. He was given Dushen Tang (Single Ginseng Decoction). After one dose, the sawing sound disappeared; after two or three doses, cough gradually receded; after consuming two or three jin, the disease completely resolved. (This is a case of Yang deficiency.)
*Bencao Yan Yi* states: Some sudden coughs do not respond to various medicines. Someone advised taking Shengliao Lurong Wan (Raw Deer Antler Pill) or Da Tusizi Wan (Large Dodder Seed Pill), leading to recovery. There is a root and a branch; one should not doubt sudden tonification just because of sudden cough. The reason for quick recovery is early detection. (This is a case of Yin deficiency.)
For a type of dry cough, Zhu Danxi said: Dry cough is extremely difficult to treat. This is a syndrome of Fire stagnation, where Phlegm stagnates Fire, with pathogen in the middle. Use Xiaoyao San (Free and Easy Wanderer Powder) to open stagnation, and use Yin-tonifying medicines below to achieve recovery.