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。
咳嗽是指没有痰但有声音。嗽是指有痰且有声音。虽然咳嗽在六腑和五脏中有不同的表现，但其关键都在于肺。因为肺是清虚的脏器，不容纳异物，毫毛受邪必致咳嗽。同时肺是娇嫩的脏器，既怕热又怕冷。火邪刑克肺金导致嗽，水冷金寒也导致嗽。因此，咳嗽必然归责于肺，但治疗的方法，不在于治肺，而在于治脾；不专在治脾，反而更重视治肾。因为脾是肺的母亲，肾是肺的儿子。所以虚证要补其母（脾），虚证也要补其子（肾）。
如果是外感风寒引起的咳嗽，现在的人通常用麻黄、枳壳、紫苏之类的药物来发散表邪，认为病从表入，就从表出。如果确实是形体和气机、病气都实盛的患者，发一次汗就能痊愈。如果形体和气机稍微虚弱的人，应该以补脾为主，辅以解表的药物。为什么呢？因为肺主皮毛，正因为肺气虚，所以腠理不紧密，风邪容易侵入。如果肺不虚，邪气从哪里进入呢？古人制作参苏饮时必定用人参，桂枝汤中必有芍药和甘草，就是在解表的同时兼以实脾。脾实则肺金得到滋养，皮毛有卫护，已侵入的邪气容易排出，后来的邪气也就无法进入了。如果专门使用解表药，那么肺气会更加虚弱，腠理更加疏松，外邪乘虚而入，什么时候才能停止呢？必须用人参、黄芪、甘草来补脾，兼用桂枝来驱邪。这就是我所说的不治肺而治脾，遵循“虚则补其母”的道理。
仁斋在《直指方》中说：肺主管呼气，肾主管纳气。肺是气的主宰，肾是气的根本。凡是咳嗽突然加重，牵动全身，自觉气从脐下逆奔而上冲的，这是肾虚不能收纳气归于元气，应当用地黄丸或安肾丸主治。不要仅仅在肺上想办法，这就是“虚则补其子”的道理。我还有进一步的论述。在五行之间，只有肺和肾两个脏腑，母亲旺盛而儿子受到邪气侵害，为什么呢？肺主气，肺有热，气受热而上蒸，不能下行生养肾，于是肾受到邪气侵害。肾既然受到邪气侵害，肺就更加生病，这又是为什么呢？因为母脏之子藏于其中，子脏之隐处于母胎之内。大凡人肺金之气，夜间睡眠时回归藏于肾水之中。如今因为肺受心火邪气侵害，想要下行躲避到水中，但肾水干枯且有火，没有容纳的地方，于是气又向上逆行而致病。
有火邪灼烧肺金导致咳嗽的，适宜清金降火。现在的医书中，论述清金降火的，用黄芩、天冬、麦冬、桑白皮来清肺金，用黄连降心火，石膏降胃火，用四物汤加黄柏、知母降阴火。认为枳壳、半夏燥湿泄气会伤阴，改用贝母、瓜蒌、竹沥、枇杷叶来润肺化痰。以上的治疗方法，难道不是平正通达吗？殊不知清金降火的道理，看似正确实则错误。补北方（肾水），正是为了泻南方（心火）。滋养其阴，就是降火的方法。难道没看到启玄子（王冰）说的“壮水之主，以制阳光”吗？我在《相火论》及《滋阴降火论》中，已经详细说明了不宜使用黄柏、知母以及寒凉诸药的危害了。我还有进一步的论述。王节斋说：凡是酒色过度，损伤肺肾真阴的人，不可服用人参、黄芪。服用过多就会死亡。大概是担心阳气旺盛而阴液消亡。自从这种说法流行后，世上治疗阴虚咳嗽的人，视人参、黄芪如砒霜毒药，视黄柏、知母为灵丹妙药，使得患此证而服用这些药的人，百无一活，实在可悲。那些能节制欲望且不服药的人，反而可以延续生命得以存活。可见并非病不可治，而是治病的方法不当。因为病本起于房劳过度，亏损真阴，阴虚则火上炎，火上炎则刑克肺金故咳嗽，咳嗽则肺金不能不受伤。我先用壮水之主的药物，如六味地黄丸之类，补其真阴，使水升而火降，随即用人参、黄芪等救肺的药物，以补肾之母，使金水相生而病易愈。世上使用寒凉药的人，多是肤浅庸碌的医生，不必多提。间或有知道使用人参、黄芪的，却不知道先壮水以镇火，就急于投用人参、黄芪以补阳，反而使阳火更加旺盛，而肺金更加受伤。难道是药的罪过吗？这就是所谓不识先后步骤的人。
有脾胃先虚，土虚不能制水，水泛溢为痰，子脏（肺）来乘母脏（脾）而咳嗽的。又有起初虽因心火刑金，因误服寒凉药，以致脾土受伤，肺更加虚弱而咳嗽的。这是在火位之下，水气承接其上，子脏（肾）来救母脏（肺），肾水复助火之仇敌（此处指寒水挟木势），寒水挟带木势而上侵于肺胃，水冷金寒故咳嗽。前面的病未除，新的病更严重。粗疏的医生不懂这个道理，还认为痰火难除，加倍进用寒凉药，岂不是危险吗？此时，必须用六君子汤加炮姜，以补脾肺；用八味丸（金匮肾气丸）以厚土母（培补脾土以生肺金），并引水归原。这些治疗咳嗽的方法，希望志同道合者多加留意。
《金匮要略》说：咳嗽且气逆，喉中有像水鸡叫的声音，用射干麻黄汤主治。这是论述外感咳嗽。
有咳嗽且声音嘶哑的，这是因为肺气实则不鸣，肺气破（虚）也不鸣。实证则清利它，虚证则补益它，都是治肺的事情。又需知道少阴经的络脉进入肺中，循行喉咙，夹舌根。肺是其标，本虚则标弱，所以声音混乱咽喉嘶哑，舌萎软声音不能发出。这出自张仲景的《伤寒论》。
有一个五十多岁的男子，患伤寒咳嗽，喉中声音如同拉锯声。给予独参汤，一服后拉锯声消除，二三服后咳嗽也逐渐减退，服用二三斤后病才完全痊愈。（这是阳虚的案例。）
《本草衍义》说：有突发咳嗽服用各种药物无效的，有人教他服用生料鹿茸丸或大菟丝子丸而痊愈。有病本有标，不可以因为其突发咳嗽，就怀疑骤然进补是不对的。之所以容易痊愈，也是因为发现得早的缘故。（这是阴虚的案例。）
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.