丹溪书呕吐门曰∶有声有物谓之呕吐，是混呕吐为一，张景岳亦不以为然，而
未尝深辨。及观李东垣则以呕为有声有物，孙真人则以吐为有物无声。详呕吐字意，当以孙、李
为是。《字汇》呕亦同讴。夫呕必有声，而 谓∶气逆则呕。盖气一逆必作声，随拥所食之物
而俱出矣。吐则较呕所出更易，开口便漾出，又岂有声哉？至于哕之一症，经中杂病篇直作呃逆，
而河间、海藏则以哕为干呕。张景岳谓呃逆古无是名。其在《内经》即谓之哕，是特古今之称名
不同。而哕与呃逆断不可混为一症也。哕虽以河间、海藏说为是。而《东垣十书·溯洄集》中则
谓哕之声浊恶长而有力，直至气尽而后止，非如干呕之轻而不甚也，是较之刘、王所说则更明白
晓畅矣。至于呃逆，即东垣所谓吃忒者，是此症称名不一，随其方言而呼之。有曰格得者，有曰
打呃者，有曰打歌得者，总与哕为二症，明系今之所谓打呃是也。《灵枢》则谓之KT ，（音噎。）
所谓KT 不得息者是也。观《金鉴》中以为格格连声，气从脐下来，自冲脉退场门作声，岂非善于
形容者乎？至于咳逆与呃逆则又不可相混，有以咳逆为呃逆者，有以咳逆为哕者，是皆未详味经
文耳。经本以咳嗽气逆为言，如气交变大论曰∶岁金太过，甚则喘咳逆气。又曰∶咳逆甚而血溢。
盖以咳嗽不止而血随
气上耳，未闻打呃而见血者也，此咳逆之非呃逆亦甚明矣。而咳逆之非哕又何待辨乎？至噫气之
说，《灵枢》云∶寒气客于胃，厥逆从下上散，复出于胃，故为噫。仲景谓∶上焦受中焦气未和，
不能消，是故能噫。据此则噫者即嗳气也，即俗之所谓拔气也，此理甚明，人所易晓。总之，有
声有物曰呕。有物无声曰吐，有声无物曰哕。呃逆者，即打呃之谓。咳逆者，咳嗽之甚，以致气
逆上冲也。噫者，《字汇》解作饱食气满而有声，岂非所谓拔气者乎？症各不同，断难相混。至
于得病之由与其治法，各有虚实寒热之异，散见诸门，兹不赘。
朱丹溪在《呕吐门》中写道：“有声音且有实物吐出称为呕吐”，这是将呕吐混为一谈，张景岳也不赞同这种观点，但未曾深入辨析。等到查看李东垣的观点，他认为“呕”是有声有物；孙思邈则认为“吐”是有物无声。详细推敲“呕吐”二字的字义，应当以孙思邈和李东垣的说法为正确。《字汇》中说“呕”也同“讴”。凡是有呕必然有声音，所以说“气逆则呕”。大概气一旦上逆必定发出声音，随即裹挟着所吃的食物一起涌出。而“吐”比“呕”排出的东西更容易，张口便漾出，又怎么会有声音呢？至于“哕”这一病症，《内经·杂病篇》直接将其作为“呃逆”，而刘河间、王好古则将“哕”解释为干呕。张景岳说“呃逆”古时没有这个名称。它在《内经》中就叫作“哕”，这仅仅是古今称呼不同罢了。然而“哕”与“呃逆”绝对不可以混为一症。“哕”虽然以刘河间、王好古的说法为是，但在《东垣十书·溯洄集》中却说“哕”的声音浑浊、恶劣、长且有力，直到气竭才停止，不像干呕那样轻微且不严重，这比刘、王所说的更加明白晓畅了。至于“呃逆”，就是李东垣所说的“吃忒”，这个病症名称不一，随着方言不同而称呼各异。有的叫“格得”，有的叫“打呃”，有的叫“打歌得”，总之都与“哕”是两种病症，明显就是现在所谓的“打呃”。《灵枢》中称之为“KT”（音噎），所谓“KT不得息”就是指此。看《医宗金鉴》中形容为格格连声，气从脐下上来，自冲脉退场门发出声音，这难道不是善于形容吗？至于“咳逆”与“呃逆”又不可相混淆，有人把“咳逆”当作“呃逆”，有人把“咳逆”当作“哕”，这都是没有仔细体味经文的原因。经文原本是用咳嗽气逆来说明的，如《素问·气交变大论》说：“岁金太过，严重时会出现喘咳逆气。”又说：“咳逆严重会导致出血。”这是因为咳嗽不止而血随气上涌罢了，没听说过打呃而出现出血的，这清楚地表明“咳逆”并非“呃逆”。那么“咳逆”并非“哕”又何待辨析呢？至于“噫气”的说法，《灵枢》说：“寒气客居于胃，厥逆之气从下向上散开，再出于胃，所以产生噫。”张仲景说：“上焦接受中焦之气但未调和，不能消化，所以能噫。”据此，“噫”就是嗳气，也就是俗话所说的“拔气”，这个道理很明白，人们容易理解。总之，有声音且有实物吐出称为“呕”；有实物无声音称为“吐”；有声音无实物称为“哕”。“呃逆”，就是打呃的意思。“咳逆”，是咳嗽剧烈，导致气逆上冲。“噫”，《字汇》解释为饱食气满而有声，这难道不就是所谓的“拔气”吗？各病症不同，绝对难以混淆。至于得病的原因及其治疗方法，各有虚实寒热之异，分散见于各门类中，此处不再赘述。
Zhu Danxi, in the section on Vomiting, stated: "That which has sound and substance is called vomiting," thereby conflating vomiting and spitting. Zhang Jingyue also did not agree with this view but did not analyze it deeply. Upon reviewing Li Dongyuan's perspective, he defined "ou" (vomiting with sound) as having both sound and substance, whereas Sun Simiao defined "tu" (spitting) as having substance without sound. A detailed examination of the characters "ou" and "tu" suggests that the views of Sun and Li are correct. The *Zihui* states that "ou" is synonymous with "ou" (to sing). Indeed, "ou" must involve sound; thus it is said that "rebellious qi causes ou." Generally, when qi rebels, it inevitably produces sound, carrying the ingested food along with it to exit. In contrast, "tu" involves material that is expelled more easily than in "ou"; it flows out upon opening the mouth, so how could there be sound?
Regarding the symptom of "yue" (hiccups/dry heaving), the *Jingmai Zabi Pian* (Chapter on Miscellaneous Diseases in the Classic) directly equates it with "e ni" (hiccup), while Liu Hejian and Wang Haoxu interpreted "yue" as dry heaving. Zhang Jingyue noted that the term "e ni" did not exist in ancient times. It was referred to as "yue" in the *Neijing*; this merely reflects differences in nomenclature between ancient and modern times. However, "yue" and "e ni" must absolutely not be confused as a single syndrome. Although the interpretations of Liu Hejian and Wang Haoxu regarding "yue" have merit, the *Suhui Ji* within the *Dongyuan Shishi* (Ten Works of Dongyuan) states that the sound of "yue" is turbid, harsh, long, and forceful, continuing until the qi is exhausted, unlike the mild nature of dry heaving. This explanation is clearer and more lucid than those of Liu and Wang. As for "e ni," it corresponds to what Dongyuan called "chi te" (hiccup). The names for this syndrome vary according to dialects: some call it "ge de," others "da e," or "da ge de." In all cases, it is distinct from "yue" and clearly refers to what is currently known as hiccup. The *Lingshu* refers to it as "KT" (pronounced 'ye'), as mentioned in the phrase "KT bu de xi" (inability to breathe due to KT). The *Yizong Jinjian* describes it vividly as a continuous "ge ge" sound, where qi rises from below the umbilicus and makes noise exiting through the Chong Mai (Penetrating Vessel) at the Tuidao point. Is this not an excellent description?
Furthermore, "ke ni" (cough with rebellious qi) and "e ni" (hiccup) must not be confused. Some mistake "ke ni" for "e ni," and others for "yue"; these errors stem from a failure to carefully interpret the canonical texts. The classics originally used cough and rebellious qi to explain such phenomena. For instance, the *Qi Jiao Bian Da Lun* (Treatise on Changes in Qi Interactions) states: "When Metal Qi is excessive, severe cases manifest as panting, coughing, and rebellious qi." It also says: "Severe coughing and rebellious qi can lead to hemorrhage." This implies that blood follows the upward-rebelling qi due to persistent coughing; one has never heard of hiccups causing hemorrhage. Thus, it is evident that "ke ni" is not "e ni." Consequently, why would "ke ni" need further differentiation from "yue"?
Regarding "yi qi" (belching), the *Lingshu* states: "Cold pathogen lodges in the Stomach, causing jue-ni (rebellious qi) to scatter upwards from below and re-emerge from the Stomach, thus producing yi." Zhang Zhongjing stated: "The Upper Jiao receives Qi from the Middle Jiao but they are not harmonized, leading to indigestion, hence yi occurs." Based on this, "yi" is equivalent to belching, commonly known in vernacular as "ba qi" (pulling qi). This logic is clear and easily understood by people.
In summary: That which has sound and substance is "ou" (vomiting); that which has substance but no sound is "tu" (spitting); that which has sound but no substance is "yue" (dry heaving/hiccup-like sound). "E ni" refers to hiccupping. "Ke ni" refers to severe coughing resulting in rebellious qi rushing upward. "Yi," as explained in the *Zihui*, refers to sound produced by fullness and excess qi after a meal, which is indeed what is called "ba qi." Since each syndrome is distinct, they cannot be confused. As for the etiology and treatment methods, they differ according to deficiency/excess and cold/heat patterns, and are discussed separately in other sections; thus, they are not repeated here.