内经云岁金太过咳逆金郁之发咳逆少阴二气咳逆
按内经所言咳逆者止此他书惟伤寒论咳逆脉散者死又金匮治咳逆上气诸方而已似皆指肺
金及
火为病也活人书谓咳逆证为极恶仲景所不载孙真人云遍寻方论无此名遂断咳逆为哕证而灵枢
云哕者谷入于胃胃气上注于肺故寒气与新谷气俱入于胃新故相乱真邪相攻气并相逆复出于胃
故为哕注云哕气仵也仵偶敌也保命集又以咳逆为噫噫气者胸中气不交也少阴经至胸中交于厥
阴水火相传而有声灵枢云噫者寒气客于胃厥逆从下上复出于胃故为噫注云噫象火烟随焰出心
不受邪故噫出之愚谓二说各有其义未知是否而难知力辨朱氏之非其论见后
活人书云咳逆者仲景所谓哕是也胃寒所生伤寒本虚攻其热必哕又云伤寒大吐下之极虚后
极汗
出者因得哕所以然者胃中寒冷故也橘皮干姜汤羌活附子散半夏生姜汤退阴散主之不瘥者灸乳
下
必愈然亦有阳证者咳逆者有潮热时时哕小柴胡汤橘皮竹茹汤又云伤寒哕而腹满视其前后何部
不利利之愈
按活人书以咳逆为哕故今从而以仲景言哕者入于咳逆之门纵使仲景言哕非此证而活人论
证用
药则是咳逆而非呕哕大抵咳逆者多由汗下之后胃虚而作活人以虚作寒治故用诸温热之药然亦
有虚而有热者有实而有热者所引橘皮竹茹汤未能详尽也
《黄帝内经》说：岁运金气太过则发生咳逆；金气郁结而发作时也会咳逆；少阴君火与厥阴风木二气失调也会导致咳逆。
考察《黄帝内经》中提到的咳逆，仅止于此。其他医书中，只有《伤寒论》提到“咳逆脉散者死”，以及《金匮要略》中治疗咳逆上气的各种方剂罢了，这些似乎都是指肺金及火邪为病。
《类证活人书》认为咳逆这一证候极为凶险，是张仲景未曾记载的。孙思邈（孙真人）说：遍寻方论，没有“咳逆”这个名称，于是断定咳逆就是哕证。而《灵枢》说：哕，是因为食物进入胃中，胃气上注于肺，所以寒气与新入胃的食物之气一同在胃中，新旧之气相乱，正气与邪气相攻，气机并逆，复出于胃，所以称为哕。注释说：哕，是指气机相忤（冲突）。忤，是偶敌（对抗）的意思。
《保命集》又将咳逆解释为噫气。噫气，是指胸中气机不交。少阴经气至胸中与厥阴经气相交，水火相传而有声。《灵枢》说：噫，是因为寒气客居于胃，厥逆之气从下向上，复出于胃，所以称为噱。注释说：噫，像火烟随着火焰冒出。心不受邪，所以噫气由此发出。
我认为这两种说法各有其道理，不知是否正确。但在难以知晓的情况下，极力辩驳朱氏（朱肱，《类证活人书》作者）的错误，其论述见后文。
《类证活人书》说：咳逆，就是张仲景所说的哕，这是由胃寒产生的。伤寒本已体虚，若再攻伐其热，必然导致哕。又说：伤寒经过大吐、大下之后，极度虚弱，随后又极汗出，因此导致哕。之所以如此，是因为胃中寒冷。用橘皮干姜汤、羌活附子散、半夏生姜汤、退阴散主治，若不愈，灸乳下穴必愈。然而也有阳证的情况，咳逆伴有潮热、时时哕，用小柴胡汤、橘皮竹茹汤。又说：伤寒出现哕且腹部胀满，观察其前后二便，哪部不利，通利之即可痊愈。
按：《类证活人书》将咳逆等同于哕，所以我现在跟随其说，将张仲景所言的哕归入咳逆的门类中。纵使张仲景所言的哕并非此证，但《类证活人书》所论述的证候和用药，确实是针对咳逆而非呕吐或哕。大抵咳逆多由汗法、下法之后，胃气虚弱所致。《类证活人书》将其作为虚寒来治，所以使用各种温热药物。然而也有虚而有热的情况，有实而有热的情况，所引用的橘皮竹茹汤未能详尽涵盖所有情况。
The *Huangdi Neijing* (Yellow Emperor's Inner Canon) states: When the metal qi of the year is excessive, cough and reverse flow (Ke Ni) occur; when metal qi is stagnant and erupts, cough and reverse flow also occur; disharmony between Shaoyin (Lesser Yin) and Jueyin (Terminal Yin) qi can also lead to cough and reverse flow.
Examining the mentions of "cough and reverse flow" in the *Huangdi Neijing*, they are limited to these instances. In other medical texts, only the *Shanghan Lun* (Treatise on Cold Damage) mentions that "if pulse is scattered in cough and reverse flow, it is fatal," and the *Jingui Yaolue* (Essential Prescriptions of the Golden Cabinet) contains various formulas for treating cough and reverse flow with upward rushing qi. These seem to refer primarily to diseases involving Lung Metal and Fire pathogens.
The *Lei Zheng Huo Ren Shu* (Book of Active People for Classifying Patterns) considers the syndrome of "cough and reverse flow" to be extremely malignant and unrecorded by Zhang Zhongjing. Sun Simiao (Sun Zhenren) stated: "Searching through all formula theories, there is no name for 'cough and reverse flow'; thus, I conclude that cough and reverse flow is synonymous with hiccups (Yue)." However, the *Lingshu* (Spiritual Pivot) states: Hiccups occur because food enters the stomach, and Stomach Qi ascends to the Lungs. Therefore, cold qi and the qi of newly ingested food enter the stomach together. The old and new qi confuse each other, righteous qi and pathogenic qi attack each other, the qi merges and reverses, and re-emerges from the stomach, hence it is called hiccups. The commentary notes: "Yue" refers to qi clashing or conflicting. "Wu" means opposing or confronting.
The *Baoming Ji* (Collection for Preserving Life) further interprets "cough and reverse flow" as belching (Yi). Belching refers to the failure of qi interaction in the chest. The Shaoyin channel reaches the chest and intersects with the Jueyin channel; water and fire transmit to each other, producing sound. The *Lingshu* states: Belching occurs because cold qi lodges in the stomach, and rebellious qi rises from below and re-emerges from the stomach, hence it is called belching. The commentary notes: Belching resembles smoke following flames. Since the Heart does not accept pathogenic qi directly, belching emanates from it.
I believe both explanations have their merits, but I am uncertain if they are correct. Given the difficulty in determining the truth, I strongly refute Zhu Shi’s (Zhu Gong’s) errors regarding this matter; his arguments are presented later.
The *Lei Zheng Huo Ren Shu* states: Cough and reverse flow is what Zhang Zhongjing referred to as hiccups (Yue), which arises from Stomach Cold. In cold damage, if the body is already deficient, attacking the heat will inevitably cause hiccups. It also states: After severe vomiting and purging in cold damage, leading to extreme deficiency, followed by profuse sweating, hiccups may result. This is because the middle jiao is cold. Treatment involves Ju Pi Gan Jiang Tang (Tangerine Peel and Dried Ginger Decoction), Qiang Huo Fu Zi San (Notopterygium and Aconite Powder), Ban Xia Sheng Jiang Tang (Pinellia and Fresh Ginger Decoction), or Tui Yin San (Retreating Yin Powder). If ineffective, moxibustion at the point below the nipple will cure it. However, there are also Yang syndrome cases where cough and reverse flow are accompanied by tidal fever and frequent hiccups, treated with Xiao Chai Hu Tang (Minor Bupleurum Decoction) or Ju Pi Zhu Ru Tang (Tangerine Peel and Bamboo Shaving Decoction). It further states: In cold damage, if hiccups are accompanied by abdominal fullness, observe the anterior and posterior orifices; whichever is obstructed, unblock it to achieve recovery.
Analysis: Since the *Lei Zheng Huo Ren Shu* equates cough and reverse flow with hiccups, I now follow its classification, incorporating Zhang Zhongjing’s discussion of hiccups under the category of cough and reverse flow. Even if Zhang Zhongjing’s “hiccups” do not exactly match this syndrome, the patterns and medications discussed in the *Lei Zheng Huo Ren Shu* indeed target cough and reverse flow rather than vomiting or simple hiccups. Generally, cough and reverse flow often arises after sweating or purging therapies due to Stomach deficiency. The *Lei Zheng Huo Ren Shu* treats this as deficiency-cold, hence using various warming and tonifying drugs. However, there are also cases of deficiency with heat and excess with heat; the cited Ju Pi Zhu Ru Tang does not exhaustively cover all scenarios.