徐叔拱曰∶咳嗽为患，所感不同，内分经络脏腑，外辨风寒暑湿燥火，冷热虚实之因。咳者声重，
从丹田下起，连咳不已，为肺气伤而不清；嗽者声轻，在上焦中起，因脾湿动而为痰。咳嗽者，有痰有声，
痰从声出，痰出而声方止是也。
治之当随脏腑四时，伤感之因，七情内伤，五脏相胜而辨治之。推其何因何脉，以用何药。假令脉
浮缓为风，风宜发散，非麻黄、细辛、旋复花、前胡之属，金沸草散、参苏饮之类，则不能散其风邪。
脉弦紧为寒，寒宜温解，非干姜、官桂、款冬、佛耳草之属，理中汤、温肺汤之类，则不能温其
寒邪。
脉虚软为暑，暑当清之，非柴胡、黄芩、地骨皮之属，六和汤中加麦冬、乌梅之类，则不清其暑毒。
脉沉涩为湿，湿当燥之，非苍术、白术辈，不换金正气
散、白术散之类，则不能燥其湿。
脉弦滑，在胃中及气口则为痰，痰当利之，非白芥子、皂角、石碱、二陈汤、导痰汤之属，非半夏、
南星、茯苓、陈皮之类，则不能去其痰涎。
脉浮盛在气口者，则为气，气当舒之，非紫苏、香附、枳壳、并香砂二陈汤、紫苏子汤、加减三奇汤
之属，则不能升降郁结之气。脉虚弱渐细者为虚，虚宜温补，非钟乳、阿胶、黄 、人参不能补肺之虚。
虚而极，作喘急，又当暖补镇坠于下。
脉弦细数者为虚劳，劳则当滋养血气，非人参、天冬、五味子、当归之属，并黄 鳖甲散、秦艽鳖甲散
之类，则不能滋养荣卫。
脉沉实有力者为气实，气实则当泄之，非葶苈、桑皮之属，以泻白散、平肺汤之类，则不能以泻肺之实。
脉濡而弱者，为肺气耗散，则宜敛之，非粟壳、诃子、乌梅酸涩之类，提金散、细辛五味汤之属，则不
能收敛肺气。
中间止有散敛二法，散者为解散寒邪，敛为收敛肺气也。宜散而敛，则敛住寒邪，为害匪轻；宜敛而
散，走泄正气，害亦非小。且如感风咳嗽，已经发散，表虚复感，虚邪相乘，又为喘咳，若欲散风则愈重
，若收敛又滞其邪，当先清解，渐次敛之，喘嗽自止矣。
喻嘉言曰∶内伤之咳，治各不同。火甚壮水，金虚崇土，郁甚舒肝，气逆理肺，食积和中，房劳补下。
内已先伤，药不宜峻。
李士材曰∶咳虽肺病，五脏六腑皆能致之。晰其条目，经文尚有漏义；总其纲领，不过内伤外感而已。
风寒暑湿伤其外，则先中于皮毛，皮毛为肺之合，肺邪
不解，他经亦病，此自肺而后传于诸脏也∶欲劳情志伤于内，则脏气受伤，先由阴分，而病及上焦，
此自诸脏而后传于肺也。
自表而入者，病在阳，宜辛温以散邪，则肺清而咳愈；自内而生者，病在阴，宜甘以壮水，润以养金
，则肺宁而咳愈。
大抵治表者药不宜静，静则流连不解，变生他病，故忌寒凉收敛，如五脏生成篇所谓肺欲辛是也；治内
者药不宜动，动则虚火不宁，燥痒愈甚，故忌辛香燥热，如宣明五气篇所谓辛走气，气病无多食辛是也。
然治表者虽宜动以散邪，若形病俱虚者，又当补中气而佐以和解。倘专于发散，恐肺气益弱，腠
理益疏，邪乘虚入，病反增剧也；治内者虽宜静以养阴，若命门火衰，不能归元，则参、 、桂、附在所
必用，否则气不化水，终无补于阴也。
随所症而调治，在老人、虚人，皆以温养补脾胃为主，稍稍治标可也。
赵养葵曰∶肺为清虚之腑，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，不专在脾而又归重于肾。盖脾者肺之母，
肾者金之子，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、紫苏之类发表
散邪。果系形气俱实，一汗而愈。若形气病气俱虚，宜补脾为主，而佐以解表之药。古人所以制参苏饮
中必有参，桂枝汤中有芍药、甘草，解表兼实脾也。脾实则肺金有养，皮毛有卫，已入之邪易以出，
后来之邪无自入矣。
又《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，
自觉气促，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，毋
徒从事于肺。此虚则补子之义也。
有火烁肺金而咳嗽者，宜清金降火。然清金降火之理，补北方正所以泻南方也，滋其阴即所
以降火也。自王节斋论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。
此说行，而世之治阴虚嗽者，视参 为砒毒，以知柏为灵丹。反不如能寡欲而不服药者，可绵延得活，可
悲也。盖病起于房劳亏损真阴，阴虚而火上刑肺金，金不能不伤。当先以壮水之主以补真阴，使水升而
火降，随以参 救肺之品，以补肾之母，使金水相生，则病易愈矣。
又有脾胃先虚，土虚不能制水，水泛为痰，子来乘母而嗽者。初虽起于心火刑金，因误服寒凉，致
脾土受伤，寒水挟木势而上，侵于肺胃，水冷金寒。粗工不达，尚谓痰火难除，寒凉倍进，不知此症须用
六君子加炮姜以补脾肺，八味丸以补土母而引水归元，否则殆矣。
有嗽而声哑者，盖金实不鸣，金破亦不鸣。实则清之，破则补之。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。
徐叔拱说：咳嗽这种病症，致病原因各不相同，内部要区分涉及的经络和脏腑，外部要辨别是感受风、寒、暑、湿、燥、火哪一类邪气，以及属于冷、热、虚、实中的哪种病因。咳的声音沉重，从丹田（脐下部位）发起，连续不断，这是肺气受伤而不清利；嗽的声音轻微，在上焦（胸膈以上）发起，是因为脾湿扰动而生痰。咳嗽并见时，既有痰又有声音，痰随声而出，痰排出来声音才停止。
治疗应当根据脏腑功能、四季气候、感伤的原因、七情（喜、怒、忧、思、悲、恐、惊）内伤以及五脏相克的关系来辨证施治。推究其病因和脉象，从而选用相应的药物。假如脉象浮缓，属于风邪，风邪适宜用发散法，如果不是用麻黄、细辛、旋复花、前胡这类药材，或者金沸草散、参苏饮这类方剂，就不能疏散风邪。
脉象弦紧，属于寒邪，寒邪适宜用温散法，如果不是用干姜、官桂、款冬、佛耳草这类药材，或者理中汤、温肺汤这类方剂，就不能温散寒邪。
脉象虚软，属于暑邪，暑邪应当用清解法，如果不是用柴胡、黄芩、地骨皮这类药材，或者在六和汤中加入麦冬、乌梅这类药物，就不能清除暑毒。
脉象沉涩，属于湿邪，湿邪应当用燥湿法，如果不是用苍术、白术这类药材，或者不换金正气散、白术散这类方剂，就不能燥化湿邪。
脉象弦滑，如果在胃经及气口（寸口脉的特定部位）出现，则属于痰证，痰证应当用利痰法，如果不是用白芥子、皂角、石碱、二陈汤、导痰汤这类方药，或者半夏、南星、茯苓、陈皮这类药材，就不能去除痰涎。
脉象浮盛在气口的，属于气滞，气滞应当用疏理法，如果不是用紫苏、香附、枳壳，或者香砂二陈汤、紫苏子汤、加减三奇汤这类方药，就不能升降郁结之气。脉象虚弱逐渐变细的，属于虚证，虚证适宜用温补法，如果不是用钟乳、阿胶、黄芪、人参，就不能补益肺虚。如果虚损严重，出现喘急，又应当用温补和镇坠的方法在下焦调理。
脉象弦细数的，属于虚劳，劳损应当滋养气血，如果不是用人参、天冬、五味子、当归这类药材，或者黄芪鳖甲散、秦艽鳖甲散这类方剂，就不能滋养营卫。
脉象沉实有力的，属于气实证，气实则应当用泻法，如果不是用葶苈、桑白皮这类药材，或者泻白散、平肺汤这类方剂，就不能泻除肺实。
脉象濡而弱的，属于肺气耗散，应当用收敛法，如果不是用粟壳、诃子、乌梅等酸涩类药物，或者提金散、细辛五味汤这类方药，就不能收敛肺气。
中间只有发散和收敛两种方法。发散是为了解散寒邪，收敛是为了收敛肺气。适宜发散却用了收敛，就会把寒邪闭留在体内，危害不小；适宜收敛却用了发散，就会导致正气外泄，危害也不小。比如感受风邪引起的咳嗽，已经用过发散法，表虚再次受邪，虚邪相乘，又出现喘咳，如果想再发散风邪则病情加重，如果想收敛又会滞留邪气，应当先清解，然后逐渐收敛，喘嗽自然就会停止。
喻嘉言说：内伤引起的咳嗽，治疗方法各不相同。火旺甚则壮水制火，肺金虚则培土生金，气郁甚则疏肝解郁，气逆则调理肺气，食积则和中消导，房劳过度则补益下元。既然内部已经先受伤，用药就不宜过于峻猛。
李士材说：咳嗽虽然是肺的病，但五脏六腑都能导致它。梳理其条目，经文还有遗漏的意义；总括其纲领，不过是内伤和外感两类而已。风寒暑湿伤害体表，先侵犯皮毛，皮毛是肺的外合，肺邪不解，其他经络也会生病，这是从肺传变到各脏；劳累或情志伤害内部，则脏气受伤，先从阴分开始，进而病及上焦，这是从各脏传变到肺。
从表入里的，病在阳，适宜用辛温药以散邪，则肺清而咳嗽痊愈；从内生发的，病在阴，适宜用甘味药以壮水，用润药以养金，则肺宁而咳嗽痊愈。
大抵治疗表证的药物不宜静止（指不宜用寒凉收敛之品），静止则病邪留恋不解，变生其他疾病，所以忌讳寒凉收敛，正如《五脏生成篇》所说“肺欲辛”；治疗里证的药物不宜动散（指不宜用辛香燥热之品），动散则虚火不宁，燥痒更甚，所以忌讳辛香燥热，正如《宣明五气篇》所说“辛走气，气病无多食辛”。
然而治疗表证虽然适宜用动散之法以驱邪，如果形体和正气都虚弱的，又应当补中气并辅以和解之法。倘若专门使用发散法，恐怕肺气更加虚弱，腠理更加疏松，邪气乘虚而入，病情反而加重；治疗里证虽然适宜用静养之法以滋阴，如果命门火衰，不能归元，那么人参、黄芪、肉桂、附子就在所必用，否则气不能化水，终究对滋阴没有帮助。
随着症状进行调治，对于老人、体虚之人，都以温养补脾胃为主，稍微兼顾治标即可。
赵养葵说：肺是清虚之腑，不容纳异物，稍有刺激必然咳嗽。肺又是娇脏，怕热怕寒，火克金故咳嗽，水冷金寒也咳嗽，所以咳嗽一定要责之于肺。但治疗的方法，不在于肺而在于脾，不专在脾而又归结重于肾。因为脾是肺的母亲，肾是肺金之子，所以虚证要补其母，也要补其子。如外感风寒引起咳嗽的，现在的人通常用麻黄、枳壳、紫苏之类发表散邪。如果是形气和病气都实的，一汗出就痊愈。如果形气、病气都虚，应当以补脾为主，辅以解表的药物。古人制作参苏饮中必须有参，桂枝汤中有芍药、甘草，就是为了在解表的同时充实脾气。脾气实则肺金得到滋养，皮毛有卫气保护，已入的邪气容易排出，后来的邪气也无从进入。
另外《仁斋直指》说：肺主呼气，肾主纳气。肺是气的主宰，肾是气的根本。凡是咳嗽突然加重，牵动全身，自觉气短急促，感觉气从脐下逆奔而上，这是肾虚不能收气归元，应当用地黄丸、安肾丸主治，不要只专注于治肺。这就是虚则补子的意义。
有因火烁肺金而咳嗽的，适宜清金降火。然而清金降火的道理，补北方（肾水）正是为了泻南方（心火），滋润阴液就是用来降火的。自从王节斋论述酒色过度损伤肺肾真阴者，不可服用人参、黄芪，服用过多则会死亡，大概是担心阳气旺盛而阴液消亡。这种说法流行后，世上治疗阴虚咳嗽的人，视人参、黄芪为砒霜毒药，视知母、黄柏为灵丹妙药。反而不如能节制欲望而不服药的人，可以延续生命，真是可悲啊。大概病起于房劳亏损真阴，阴虚而火上刑克肺金，肺金不能不受伤。应当先用壮水之主的方法来补真阴，使水升而火降，随后用人参、黄芪等救肺的药物，以补肾之母（土生金，此处意指通过补气以助金水相生），使金水相生，则病容易痊愈。
又有脾胃先虚，土虚不能制水，水泛为痰，子（水）来乘母（金）而咳嗽的。起初虽起于心火刑金，因误服寒凉药，导致脾土受伤，寒水挟带木势而上，侵于肺胃，水冷金寒。粗劣的医生不懂此理，还认为痰火难除，加倍进用寒凉药，不知道此症须用六君子汤加炮姜以补脾肺，用八味丸以补土母而引水归元，否则就危险了。
有咳嗽而声音嘶哑的，这是因为金实不鸣，金破亦不鸣。实证则清之，虚损（破）则补之。又须知少阴肾经的络脉入肺中，循喉咙，挟舌本，肺是标，本虚则标弱，所以声音混乱咽喉嘶哑，舌萎软声音发不出。
Xu Shugong stated: Cough is a disease with varying causes. Internally, one must distinguish the meridians and zang-fu organs involved; externally, one must differentiate between wind, cold, summerheat, dampness, dryness, and fire pathogens, as well as determine whether the etiology is cold, heat, deficiency, or excess. "Ke" (cough proper) features a heavy sound originating from the Dantian (lower abdomen), occurring continuously, indicating lung qi injury and lack of clarity. "Sou" (phlegm expectoration) features a light sound originating in the Upper Jiao (chest and above), caused by spleen dampness stirring up phlegm. When both occur together ("Ke Sou"), there is both phlegm and sound; the phlegm exits with the sound, and the sound ceases only when the phlegm is expelled.
Treatment should be differentiated based on zang-fu functions, the four seasons, the cause of pathogenic invasion, internal injury from the Seven Emotions (joy, anger, worry, overthinking, grief, fear, fright), and the mutual overcoming relationships among the five zang organs. One must deduce the specific cause and pulse pattern to select appropriate herbs. For instance, if the pulse is floating and moderate (Fu Huan), it indicates Wind; Wind pathogens require dispersing methods. Without herbs such as Ephedrae Herba (Mahuang), Asari Radix (Xixin), Inulae Flos (Xuanjinhua), or Peucedani Radix (Qianhu), or formulas like Jinfei Cao San (Golden Boiling Grass Powder) or Shen Su Yin (Ginseng and Perilla Decoction), the wind pathogen cannot be dispersed.
If the pulse is wiry and tight (Xuan Jin), it indicates Cold; Cold pathogens require warming and resolving methods. Without herbs such as Zingiberis Rhizoma (Ganjiang), Cinnamomi Cortex (Guigui), Dendrobii Caulis (Kudong), or Petasitae Flos (Foercao), or formulas like Lizhong Tang (Regulate the Middle Decoction) or Wen Fei Tang (Warm Lung Decoction), the cold pathogen cannot be warmed away.
If the pulse is deficient and soft (Xu Ruan), it indicates Summerheat; Summerheat requires clearing and resolving. Without herbs such as Bupleuri Radix (Chaihu), Scutellariae Radix (Huangqin), or Lycii Cortex (Digupi), or adding Ophiopogonis Tuber (Maidong) and Mume Fructus (Wumei) to Liuhe Tang (Six Harmonies Decoction), the summerheat toxin cannot be cleared.
If the pulse is deep and choppy (Chen Se), it indicates Dampness; Dampness requires drying. Without herbs such as Atractylodis Rhizoma (Cangzhu) or Atractylodis Macrocephalae Rhizoma (Baizhu), or formulas like Buhuanjin Zhengqi San (Non-Exchangeable Upright Qi Powder) or Baizhu San (Atractylodes Powder), the dampness cannot be dried.
If the pulse is wiry and slippery (Xuan Hua), appearing at the Stomach meridian or Qikou (pulse position at the radial artery), it indicates Phlegm; Phlegm requires draining and eliminating. Without herbs such as Brassicae Semen Album (Baijiezi), Gleditsiae Sinensis Fructus (Zaojiao), Natron (Shijian), or formulas like Erchen Tang (Two-Cured Decoction) or Daotan Tang (Leading Out Phlegm Decoction), or herbs like Pinelliae Rhizoma (Banxia), Arisaematis Rhizoma (Nanxing), Poria (Fuling), and Citri Reticulatae Pericarpium (Chenpi), the phlegm-fluids cannot be removed.
If the pulse is floating and vigorous at the Qikou, it indicates Qi stagnation; Qi stagnation requires soothing and regulating. Without herbs such as Perillae Folium (Zisu), Cyperi Rhizoma (Xiangfu), Aurantii Fructus (Zhike), or formulas like Xiangsha Erchen Tang (Cyperi and Amomi Two-Cured Decoction), Zi Su Zi Tang (Perilla Seed Decoction), or Jiajian Sanqi Tang (Modified Three Wonders Decoction), the stagnant qi cannot be regulated. If the pulse is weak and gradually thin, it indicates Deficiency; Deficiency requires warming and tonifying. Without Hermodactylis Tubers (Zhongru), Donkey-hide Gelatin (Ejiao), Astragali Radix (Huangqi), or Ginseng Radix et Rhizoma (Renshen), lung deficiency cannot be tonified. If deficiency is extreme and leads to panting and urgency, one must apply warming tonification and sedative/heavy methods targeting the Lower Jiao.
If the pulse is wiry, fine, and rapid (Xuan Xi Shu), it indicates Consumption (Xu Lao); Consumption requires nourishing blood and qi. Without herbs such as Ginseng Radix et Rhizoma (Renshen), Ophiopogonis Tuber (Tiantong), Schisandrae Fructus (Wuweizi), or Angelicae Sinensis Radix (Danggui), or formulas like Huangqi Biejia San (Astragalus and Turtle Shell Powder) or Qinjiao Biejia San (Gentian and Turtle Shell Powder), Ying and Wei cannot be nourished.
If the pulse is deep, solid, and forceful (Chen Shi Youli), it indicates Excess of Qi; Excess requires purging. Without herbs such as Lepidii Fructus (Tingli) or Morus Cortex Sangbai Pi (Sangpi), or formulas like Xie Bai San (Drain White Powder) or Ping Fei Tang (Calming Lung Decoction), lung excess cannot be purged.
If the pulse is soggy and weak (Ru Ruo), it indicates consumption and dispersion of lung qi; this requires astringing. Without astringent herbs such as Cornus Fructus (Suke), Chebulae Fructus (Hezi), or Mume Fructus (Wumei), or formulas like Tijin San (Extract Gold Powder) or Xixin Wuwei Tang (Asari and Schisandra Decoction), lung qi cannot be astringed.
There are essentially only two methods here: dispersing and astringing. Dispersing aims to resolve cold pathogens, while astringing aims to consolidate lung qi. If dispersing is indicated but astringents are used, the cold pathogen will be trapped, causing significant harm; if astringing is indicated but dispersants are used, healthy qi will leak out, also causing significant harm. For example, in wind-induced cough that has already been treated with dispersants, if the exterior is deficient and re-infected by deficient pathogens, leading to renewed panting and cough, using more dispersants will worsen the condition, while using astringents will retain the pathogen. One should first clear and resolve, then gradually astringe, and the panting and cough will cease naturally.
Yu Jiayan stated: Cough due to internal injury varies in treatment. If fire is excessive, nourish water to control it; if metal (lung) is deficient, strengthen earth (spleen) to generate it; if depression is severe, soothe the liver; if qi is rebellious, regulate the lung; if food stagnation exists, harmonize the middle; if sexual exhaustion occurs, tonify the lower jiao. Since the interior is already injured, medications should not be overly harsh.
Li Shicai stated: Although cough is a lung disease, all zang and fu organs can cause it. Analyzing its details, the classics may still have omitted meanings; summarizing its principles, it boils down to internal injury and external contraction. External pathogens (wind, cold, summerheat, dampness) attack the exterior, first affecting the skin and hair. Skin and hair are the exterior extension of the lung; if lung pathogens are not resolved, other meridians become diseased. This is transmission from the lung to other organs. Internal injury from fatigue or emotions damages organ qi, starting from the yin aspect and affecting the upper jiao. This is transmission from other organs to the lung.
When entering from the exterior, the disease is in yang; it is suitable to use acrid-warm herbs to disperse pathogens, clearing the lung and curing the cough. When arising from within, the disease is in yin; it is suitable to use sweet herbs to nourish water and moistening herbs to nourish metal, calming the lung and curing the cough.
Generally, drugs for treating exterior syndromes should not be static (astringent/cold); if static, pathogens linger unresolved and transform into other diseases. Therefore, cold and astringent herbs are contraindicated, as stated in the *Chapter on Generation of Five Zang Organs*: "The lung desires acridity." Drugs for treating interior syndromes should not be moving (dispersing/drying); if moving, deficient fire becomes unsettled and dryness/itching worsens. Therefore, acrid-aromatic and drying-hot herbs are contraindicated, as stated in the *Chapter on Manifestations of Five Qi*: "Acridity moves qi; in qi disorders, do not consume much acridity."
However, although treating exterior syndromes favors movement to disperse pathogens, if both form and qi are deficient, one must tonify middle qi and assist with harmonizing methods. If one specializes only in dispersing, lung qi may weaken further, pores may loosen, and pathogens may enter through deficiency, worsening the illness. Although treating interior syndromes favors stillness to nourish yin, if Mingmen fire declines and fails to return to its root, Ginseng Radix et Rhizoma (Renshen), Astragali Radix (Huangqi), Cinnamomi Ramulus (Guizhi), and Aconiti Lateralis Radix Praeparata (Fuzi) are essential. Otherwise, qi cannot transform fluids, and there will ultimately be no benefit to yin.
Treatment should follow symptoms. For the elderly and the deficient, the primary approach is warming and nourishing the spleen and stomach, with slight attention to symptomatic relief.
Zhao Yangkui stated: The lung is a pure and hollow organ, tolerating no foreign matter; even slight irritation causes cough. The lung is also a delicate organ, fearing heat and cold. Fire punishing metal causes cough; cold water and cold metal also cause cough. Thus, cough must be attributed to the lung. However, the method of treatment lies not in the lung but in the spleen, and specifically emphasizes the kidney. The spleen is the mother of the lung; the kidney is the son of metal. Therefore, in deficiency, one tonifies the mother and the son. For example, in cough due to external wind-cold, people usually use Ephedrae Herba (Mahuang), Aurantii Fructus (Zhike), or Perillae Folium (Zisu) to release the exterior and disperse pathogens. If both form and qi are substantial, one sweating episode cures it. If form, qi, and pathology are all deficient, one should prioritize tonifying the spleen, assisted by exterior-releasing herbs. This is why Shen Su Yin (Ginseng and Perilla Decoction) contains Ginseng Radix et Rhizoma (Renshen), and Guizhi Tang (Cinnamon Twig Decoction) contains Paeoniae Radix Alba (Shaoyao) and Glycyrrhizae Radix et Rhizoma (Gancao)—to release the exterior while strengthening the spleen. When the spleen is solid, lung metal is nourished, and the skin/hair have protective qi. Existing pathogens exit easily, and new pathogens cannot enter.
Furthermore, *Renzhai Zhizhi* states: The lung exhales qi; the kidney receives qi. The lung is the master of qi; the kidney is the root of qi. In sudden, severe cough that agitates the whole body, with shortness of breath and a sensation of qi rushing upward from below the umbilicus, this is kidney deficiency failing to receive qi and return it to its root. One should treat with Dihuang Wan (Rehmannia Pill) or Anshen Wan (Peace Kidney Pill), rather than focusing solely on the lung. This illustrates the principle of tonifying the son in deficiency.
In cases where fire scorches lung metal causing cough, one should clear metal and descend fire. The principle of clearing metal and descending fire is that tonifying the North (Kidney Water) drains the South (Heart Fire); nourishing yin is the method to descend fire. Since Wang Jiezai discussed how excessive alcohol and sex damage the true yin of the lung and kidney, and that Ginseng Radix et Rhizoma (Renshen) and Astragali Radix (Huangqi) should not be taken, as excessive use leads to death (fearing yang prosperity and yin depletion), this view became prevalent. Consequently, those treating yin-deficiency cough regard Ginseng Radix et Rhizoma (Renshen) and Astragali Radix (Huangqi) as arsenic poison and Anemarrhenae Rhizoma (Zhimu) and Phellodendri Cortex (Huangbai) as spiritual elixirs. It is better to practice moderation and abstain from medicine to prolong life, which is tragic. Since the disease arises from sexual exhaustion damaging true yin, yin deficiency allows fire to punish lung metal, inevitably injuring the lung. One should first use methods to strengthen the source of water to tonify true yin, allowing water to rise and fire to descend, then use Ginseng Radix et Rhizoma (Renshen) and Astragali Radix (Huangqi) to rescue the lung and tonify the mother of the kidney (Earth generates Metal), facilitating the interaction of metal and water, leading to recovery.
In cases where spleen and stomach are initially deficient, earth deficiency fails to control water, water floods and transforms into phlegm, and the "son" (water/kidney) attacks the "mother" (metal/lung) causing cough. Initially, this may stem from heart fire punishing metal, but due to mistaken use of cold-cooling herbs, spleen earth is injured. Cold water, aided by wood, rises and invades the lung and stomach, causing cold water and cold metal. Unskilled physicians, unaware of this, believe phlegm-fire is hard to remove and increase cold-cooling herbs. They fail to realize this syndrome requires Liujunzi Tang (Six Gentlemen Decoction) with Paeoniae Radix Alba Shaoyao (Paojiang - fried ginger) to tonify spleen and lung, and Bawei Wan (Eight-Ingredient Pill) to tonify the earth mother and guide water back to its root; otherwise, it is perilous.
In cough with hoarseness, it is said that "full metal does not ring, broken metal does not ring either." Excess is cleared; deficiency (breakage) is tonified. Also, note that the collateral of Shaoyin enters the lung, follows the throat, and binds to the base of the tongue. The lung is the branch; if the root is deficient, the branch is weak. Thus, voice becomes chaotic, throat hoarse, tongue flaccid, and speech difficult.