夏禹铸曰。前书只说风寒暑湿燥火。六淫之邪气侵肺。皆令人嗽。又曰。五脏六腑皆有嗽。非独在肺。此仅言咳嗽
之大纲。卒未透发。六淫侵肺之颜色。与脏腑俱嗽之分别。余忆其故。必从大方脉书上采来。惟照脉论症。故不说到六
淫侵肺的颜色。亦未分疏脏腑致嗽的根由。即言一一形症。俱属模糊。余把六淫侵肺脏腑皆嗽这八个字上。一一体出形
色。历药不爽。若风寒湿三邪侵肺。其候面白而畏风。烧热而无汗。或头疼。或鼻流清涕。唇色晦暗。痰涎白色。或滑
而易出。小便清长。便知为风寒与湿气所侵。宜用疏风顺气汤。或清肺饮。去白术。加防风。便愈。
火侵肺嗽。与火炎无制相同。方见后。若燥侵肺嗽。其候头面汗出。寒热往来。皮肤干燥。皮疮瘙痒。大便闭结。
痰涎胶粘。治宜润肺清金之剂。用麦冬、贝母、冬花、黄芩、防风、麻仁、甘草、赤芍、陈皮。暑气侵肺而嗽。其候口
渴唇淡。治宜香薷、浓朴、扁豆。加冬花、麦冬。至于六淫皆嗽之说。殊属大概。余着实穷究。六淫之外。嗽又有五。
一顺传。一逆克。一反侮。一隔经传染。一水火不相交济。
顺传之嗽在脾。脾不能生金。金无土养。故嗽。汉武帝金钟自鸣。东方朔曰。土其母也。母丧则子鸣。出必有崩者。
久之。蜀郡有奏山崩。以此悟之。脾虚肺嗽。乃一定之理。其候唇口惨白。气弱神疲。小便清短。大便或溏泻。淡淡白
色。便知脾嗽。治用六君子汤自愈。
逆克之嗽在心。心火盛。则金被火伤而嗽。试观冶人烁金。火烈而金跃。息火则金安。火克金沸。亦一定之理。其
候舌红唇燥。小便赤涩。口气蒸手。便知心火克金。法惟泻心。用贝母、陈皮、甘草、黄连。木通、杏仁、麦冬、
五味等分。灯心引。煎服三四剂。自愈。
弱克之嗽在肝。肝有制伏。肝始不旺。如肺弱木强。侮金。则肺乃被侮而嗽。肝侮肺嗽。又一定之理。其
候目勇口苦。宜用白芍、柴胡、冬花、五味、枳壳、半夏、甘草等分。煎服五剂自愈。
水火不相交济之嗽。由肾水不能上升。则火炎无制。乃上刑肺金而嗽。犹之易之未济。离火居上。坎水居下。
水不得火而无功。火不得水而功亦无所施。水火不相交。故不各得其用。若既济。则为有用矣。况五行惟火最烈。
岂止嗽耶。其症涕唾带血。甚至血溢。治用滋阴降火汤。二三剂自愈。屡治屡效。案难悉载。
隔经传染之嗽在胃。胃有热因染乎肺而嗽。肺胃各经。顺传不到。逆克不及。又不相侮。胡为亦嗽。乃由胃
肺逼邻。胃司食入。肺司气出。出入虽不同途。却共呼吸门户。胃热熏蒸。波及肺窍。所谓失火殃鱼。亡猿灾木者
是也。其候唇红口红作渴。气出大热。治用石膏、冬花、麻仁、五味、甘草。
以上诸嗽。如喘。加麦冬、天冬。如咳有声无痰。加杏仁、防风。有声有痰。加半夏、枳壳。
余于本经咳嗽外。复将此五种。旁引曲喻。无非为嗽。虽出自肺家。而却有隔经之嗽。理实虽明。故不惜多方
以譬明耳。幸毋以卮言罪我。
江平世业医道。地距四十余里。一孙咳嗽。自药不应。以形色札白之余。并来药单。乃泻肺之味。掳曰。面舌
唇口皆红。小便赤色。余札复。示以泻心之剂。后闻三剂愈。此心火刑金。泻心救肺之一验也。
夏禹铸说：以前的医书只提到风、寒、暑、湿、燥、火这六淫邪气侵袭肺脏，都会导致咳嗽。又说五脏六腑都有咳嗽，并不仅仅局限于肺。这仅仅是论述了咳嗽的大纲，并没有透彻阐明六淫侵袭肺部的具体征象，以及脏腑致咳的区别所在。我回忆其原因，必定是从内科（大方脉）书籍中摘录而来，只是依据脉象来论症，所以没有讲到六淫侵袭肺部的面色表现，也没有详细分辨脏腑导致咳嗽的根本原因。即使列举了各种症状，也都属于模糊不清。我将“六淫侵肺”和“脏腑皆嗽”这八个字，逐一推演出其具体的形色表现，用药从未失误。
如果是风、寒、湿三种邪气侵袭肺脏，其表现为面色苍白且怕风，发热但没有汗出，或者头痛，或者鼻流清涕，嘴唇颜色晦暗，痰涎白色，或者稀滑容易咳出，小便清长，就可以知道是风寒与湿气所侵袭。适宜使用疏风顺气汤，或者清肺饮，去掉白术，加入防风，即可痊愈。
火邪侵袭肺脏导致的咳嗽，与火势炎上无法制约的情况相同，方剂见后文。如果是燥邪侵袭肺脏导致的咳嗽，其表现为头面部出汗，忽冷忽热，皮肤干燥，皮肤生疮瘙痒，大便闭结不通，痰涎胶粘难咯。治疗适宜用润肺清金的药剂。药用麦冬、贝母、款冬花、黄芩、防风、麻仁、甘草、赤芍、陈皮。
暑气侵袭肺脏导致的咳嗽，其表现为口渴、嘴唇淡白。治疗适宜用香薷、厚朴、扁豆，加入款冬花、麦冬。至于六淫都导致咳嗽的说法，确实比较笼统。我深入探究发现，除了六淫之外，咳嗽还有五种情况：一是顺传，二是逆克，三是反侮，四是隔经传染，五是水火不相交济。
顺传引起的咳嗽在脾脏。脾不能生金（土不生金），肺金没有土的滋养，所以咳嗽。汉武帝时金钟自鸣，东方朔说：“土是它的母亲，母亲去世儿子就会鸣叫，出门必有山崩。”后来很久，蜀郡奏报山崩，由此领悟到这一道理。脾虚导致肺咳，是一定的道理。其表现为嘴唇口角惨白，气弱神疲，小便清短，大便或溏泻，颜色淡淡白色，就可以知道是脾咳。治疗用六君子汤即可自愈。
逆克引起的咳嗽在心脏。心火旺盛，则金被火伤而咳嗽。试看冶炼工人熔炼金属，火势猛烈金属就跳跃，熄灭火势金属就安定。火克金沸腾，也是一定的道理。其表现为舌头红、嘴唇干燥，小便赤涩，口气热气熏手，就可以知道是心火克金。治法只有泻心火。药用贝母、陈皮、甘草、黄连、木通、杏仁、麦冬、五味子等分，用灯心草为引，煎服三四剂，即可自愈。
反侮引起的咳嗽在肝脏。肝有制约才能不亢盛，如果肺弱木强，木侮金，那么肺就被侮而咳嗽。肝侮肺咳嗽，也是一定的道理。其表现为眼睛怒视、口苦。适宜用白芍、柴胡、款冬花、五味子、枳壳、半夏、甘草等分，煎服五剂即可自愈。
水火不相交济引起的咳嗽，是由于肾水不能上升，导致火炎上无法制约，从而向上刑克肺金而咳嗽。这就如同《易经》中的未济卦，离火居上，坎水居下。水得不到火就没有功效，火得不到水功效也无法施展。水火不相交，所以各自不能发挥效用。如果是既济卦，就是有用的了。况且五行中火最猛烈，岂止是咳嗽呢？其症状为鼻涕唾液中带血，甚至吐血。治疗用滋阴降火汤，二三剂即可自愈，屡治屡效。案例难以全部记载。
隔经传染引起的咳嗽在胃脏。胃中有热邪感染肺脏而导致咳嗽。肺经和胃经之间，顺传不到，逆克不及，也不相侮，为什么也会咳嗽呢？这是因为胃和肺位置相邻，胃主管食物进入，肺主管气体呼出。出入虽然路径不同，却共用呼吸的门户。胃热熏蒸，波及肺窍，这就是所谓的“失火殃鱼，亡猿灾木”。其表现为嘴唇红、口腔红、口渴，呼出的气体大热。治疗用石膏、款冬花、麻仁、五味子、甘草。
以上各种咳嗽，如果伴有气喘，加麦冬、天冬。如果咳嗽有声但无痰，加杏仁、防风。如果咳嗽有声且有痰，加半夏、枳壳。
我在本经关于咳嗽的论述之外，又对此五种情况旁征博引、曲折比喻，无非是为了说明咳嗽，虽然出自肺家，但却有隔经传来的咳嗽。道理虽然明白，所以不惜多方来譬喻阐明它。希望不要以支离破碎之言怪罪我。
江平世代行医，距离四十多里。他的一个孙子咳嗽，自己服药无效，便把面色形态写在纸上寄给我，并附上药单，那是泻肺的药物。我看后写道：面、舌、唇、口都红，小便赤色。我回信给他，指示使用泻心的药剂。后来听说三剂就好了。这是心火刑金，通过泻心来救肺的一个验证案例。
Xia Yuzhu said: Previous medical texts only mentioned that the six pathogenic factors (Liu Yin, 六淫) of wind, cold, summerheat, dampness, dryness, and fire invading the Lung organ all cause cough. It is also stated that cough can arise from all five Zang organs and six Fu organs, not solely limited to the Lung. This merely outlines the general principles of cough, without thoroughly elucidating the specific manifestations of the six pathogenic factors invading the Lung, nor distinguishing the root causes of cough arising from different Zang-Fu organs. I recall that this must have been excerpted from internal medicine (Da Fang Mai, 大方脉) books; they relied solely on pulse diagnosis to discuss symptoms, thus failing to describe the facial complexion associated with the six pathogenic factors invading the Lung, nor did they clarify the origins of cough caused by various Zang-Fu organs. Even when listing various symptoms, they remained vague. By analyzing the eight characters "six pathogenic factors invade the Lung" and "all Zang-Fu organs cause cough," I deduced their specific physical signs and colorations, and my prescriptions have never failed.
If the three pathogens of wind, cold, and dampness invade the Lung, the presentation includes a pale complexion and aversion to wind, fever without sweat, headache, or runny clear nasal discharge, dark lips, white phlegm that is either slippery and easy to expectorate, and clear, copious urine. One can then determine it is invaded by wind-cold and dampness. It is appropriate to use Shufeng Shunqi Tang (Wind-Dispersing Qi-Regulating Decoction), or Qingfei Yin (Lung-Clearing Drink), removing Baizhu (Atractylodis Rhizoma) and adding Fangfeng (Saposhnikoviae Radix), which will lead to recovery.
Cough caused by Fire invading the Lung is similar to uncontrolled flaming fire; the prescription is found later in the text. If Dryness invades the Lung causing cough, the presentation includes sweating on the head and face, alternating chills and fever, dry skin, pruritic skin sores, constipation, and sticky, difficult-to-expectorate phlegm. Treatment should employ moistening-Lung and clearing-Metal agents. The herbs used are Maidong (Ophiopogonis Radix), Beimu (Fritillariae Bulbus), Donghua (Dendrobii Caulis), Huangqin (Scutellariae Radix), Fangfeng (Saposhnikoviae Radix), Maren (Cannabis Semen), Gancao (Glycyrrhizae Radix et Rhizoma), Chishao (Paeoniae Radix Rubra), and Chenpi (Citri Reticulatae Pericarpium).
Cough caused by Summerheat invading the Lung presents with thirst and pale lips. Treatment should use Xiangru (Elsholtziae Herba), Houpo (Magnoliae Officinalis Cortex), and Bian Dou (Dolichoris Semen), added with Donghua (Dendrobii Caulis) and Maidong (Ophiopogonis Radix). As for the statement that all six pathogenic factors cause cough, it is indeed too general. Upon thorough investigation, I found that besides the six pathogenic factors, there are five other types of cough: one is Shunchuan (Sequential Transmission), one is Nike (Inverse Overcoming), one is Fanwu (Reverse Insult), one is Gejing Chuangan (Transmission Across Meridians), and one is Shuihuo Bu Xiang Jiaoji (Failure of Water and Fire to Interact).
Cough due to Shunchuan (Sequential Transmission) originates in the Spleen. When the Spleen fails to generate Metal (Earth fails to nourish Metal), the Lung Metal lacks Earth's nourishment, resulting in cough. When the bronze bell rang spontaneously during Emperor Wu of Han's reign, Dongfang Shuo said, "Earth is its mother; if the mother dies, the son cries, indicating an impending collapse." Later, a report arrived from Shu Commandery about a mountain collapse, leading to this realization. Spleen deficiency causing Lung cough is a fixed principle. The presentation includes pale lips and mouth, weak Qi, mental fatigue, clear and short urine, loose stools or diarrhea with pale color. One can identify this as Spleen cough. Treatment with Liujunzi Tang (Six-Gentlemen Decoction) leads to self-healing.
Cough due to Nike (Inverse Overcoming) originates in the Heart. Excessive Heart Fire injures Metal, causing cough. Observe metalworkers smelting metal: intense fire makes metal jump, while extinguishing the fire calms the metal. Fire overcoming Metal causing boiling is a fixed principle. The presentation includes a red tongue, dry lips, red and scanty urine, and hot breath that feels warm to the touch. One can identify Heart Fire overcoming Metal. The method is to purge Heart Fire. The herbs are Beimu (Fritillariae Bulbus), Chenpi (Citri Reticulatae Pericarpium), Gancao (Glycyrrhizae Radix et Rhizoma), Huanglian (Coptidis Rhizoma), Mutong (Akebiae Caulis), Xingren (Armeniacae Semen Amarum), Maidong (Ophiopogonis Radix), and Wuweizi (Schisandrae Fructus) in equal parts, decocted with Dengxincao (Junci Medulla) as a guide, taken for three to four doses for self-healing.
Cough due to Fanwu (Reverse Insult) originates in the Liver. The Liver must be restrained to prevent hyperactivity; if the Lung is weak and Wood is strong, Wood insults Metal, causing the Lung to be insulted and cough. Liver insulting Lung cough is a fixed principle. The presentation includes glaring eyes and bitter taste in the mouth. It is appropriate to use Baishao (Paeoniae Radix Alba), Chaihu (Bupleuri Radix), Donghua (Dendrobii Caulis), Wuweizi (Schisandrae Fructus), Zhike (Aurantii Fructus Immaturus), Banxia (Pinelliae Rhizoma), and Gancao (Glycyrrhizae Radix et Rhizoma) in equal parts, decocted and taken for five doses for self-healing.
Cough due to the failure of Water and Fire to interact arises because Kidney Water cannot ascend, leading to uncontrolled flaming fire that insults Lung Metal from above. This is like the Wei Ji hexagram in the I Ching, where Li Fire resides above and Kan Water resides below. Water without Fire has no efficacy, and Fire without Water cannot exert its function. Because Water and Fire do not interact, neither achieves its purpose. If they were in the Ji Ji state, they would be useful. Moreover, among the Five Elements, Fire is the most fierce; how could it be limited to just cough? The symptoms include blood in nasal discharge and saliva, even hemoptysis. Treatment uses Ziyin Jianghuo Tang (Nourishing Yin and Descending Fire Decoction); two to three doses lead to self-healing. It has been effective repeatedly. Cases are too numerous to record fully.
Cough due to Gejing Chuangan (Transmission Across Meridians) originates in the Stomach. Heat in the Stomach infects the Lung, causing cough. Between the Lung and Stomach meridians, Shunchuan does not reach, Nike does not occur, and there is no mutual insult. Why does cough still occur? It is because the Stomach and Lung are adjacent. The Stomach governs food intake, and the Lung governs Qi exhalation. Although entry and exit follow different paths, they share the portal of respiration. Stomach heat steaming affects the Lung orifices, akin to "fire spreading to fish when lost, disaster reaching trees when the ape flees." The presentation includes red lips and oral mucosa, thirst, and hot exhaled air. Treatment uses Shigao (Gypsum Fibrosum), Donghua (Dendrobii Caulis), Maren (Cannabis Semen), Wuweizi (Schisandrae Fructus), and Gancao (Glycyrrhizae Radix et Rhizoma).
For the aforementioned coughs: if accompanied by wheezing, add Maidong (Ophiopogonis Radix) and Tiandong (Asparagi Radix). If coughing with sound but no phlegm, add Xingren (Armeniacae Semen Amarum) and Fangfeng (Saposhnikoviae Radix). If coughing with sound and phlegm, add Banxia (Pinelliae Rhizoma) and Zhike (Aurantii Fructus Immaturus).
Beyond the discussion of cough in this classic, I have further cited examples and used metaphors for these five types. This is merely to explain that although cough originates in the Lung, there are coughs transmitted across meridians. Although the principle is clear, I did not spare effort to illustrate it through various analogies. I hope you do not blame me for using trivial words.
Jiang Ping practiced medicine for generations, residing over forty li away. His grandson suffered from cough, which did not respond to his own medication. He sent me a note describing his complexion and a list of his prescribed medicines, which were purgatives for the Lung. I observed that the face, tongue, lips, and mouth were all red, and the urine was red. I replied with a note instructing him to use a Heart-purging formula. Later, I heard he recovered after three doses. This is a verification case of Heart Fire insulting Metal, saving the Lung by purging the Heart.