伤寒哕者。何以明之。哕者俗谓之咳逆者是也。KT （音噎）近于哕。KT 者但胸喉间气。KT 塞不得下通。
然而无
声也。若哕则吃吃然有声者是也。哕者成金也。胃受疾故哕。
哕也。KT 皆胃之疾。但轻重有差尔。虚寒相搏。反饮水令汗大出。水得寒气。冷必
相搏。其人即KT 。言胃气虚竭也。伤寒大吐大下之后。极虚复极汗出者。其人外气
怫郁。复与之水。以发其汗。因得哕。所以然者。胃中寒冷故也。又胃中虚冷。不能食
者。饮水则哕。即是观之哕、KT 皆胃疾可知矣。经曰。趺阳脉浮。则为气KT 。脉滑则为
哕。此为医咎。责虚取实之过也。大抵妄下之后。胃虚气逆。则成哕也。经曰。湿家若
下之太早则哕。本虚攻其热则哕。而阳明病不能食。攻其热必哕。诸如此者。皆下
之后。胃虚而哕者也。然KT 者正为水寒相搏。必曰小青龙汤去麻黄加附子而可
矣。至于哕者。则又热气壅郁。气不得通而成者也。轻者有和解之证。重者有攻下
之候。经曰。有潮热时时哕。与小柴胡汤者。即是和解之证也。哕而腹满。视其前后。
知何部不利。利之则愈。即可攻下之候也。伤寒至于哕。则病已极也。非若渴烦等
轻缓之候。如太阳中风。以火劫发汗。阴阳俱虚竭。身体枯燥。但头汗出。剂颈而还。
腹满微喘。口干咽烂。或不大便。久则谵语。甚者至哕。是言其极也。又不尿。腹满加
哕者不治。是为真病。其若是者。虽有神医之术。当斯脱绝之候。又何以措其手足
哉。
伤寒病中出现呃逆（打嗝）症状，该如何阐明其机理呢？呃逆就是民间所说的“咳逆”。欬噎（音同“噎”，指气逆堵塞感）与呃逆相近。欬噎只是胸喉间气机壅塞，不能向下通畅，然而没有声音。而呃逆则是发出吃吃有声的症状。呃逆在五行中属金，是因为胃受疾病影响所致。呃逆和欬噎都是胃的疾病，只是轻重程度有所不同。
如果是虚寒之邪相互搏结，反而让人饮水以求大汗出，水遇到寒气，冷必相互搏结，病人就会发生欬噎，这是说胃气虚弱枯竭的缘故。伤寒病经过大吐、大下之后，身体极度虚弱，又出现极度汗出的情况，此时病人体表气机郁滞不畅，医生再给予饮水以发汗，因此导致呃逆。之所以这样，是因为胃中寒冷的缘故。另外，如果胃中虚冷，不能进食，喝水就会导致呃逆。从这些情况来看，可知呃逆和欬噎都是胃部的疾病。
《内经》说：趺阳脉浮，则为气机壅塞的欬噎；脉滑则为呃逆。这是医生的过错，属于对虚证误用攻伐实证的错误治疗。大抵误用下法之后，胃气虚弱，气机上逆，就会形成呃逆。《内经》又说：患有湿病的患者，如果过早使用下法，会导致呃逆；本身体虚却攻伐其热邪，会导致呃逆；阳明病患者不能进食，攻伐其热邪必然导致呃逆。诸如此类情况，都是因为下法之后，胃气虚弱而导致呃逆。
然而，欬噎是因为水寒之气相互搏结，必须用小青龙汤去掉麻黄，加入附子才可以治愈。至于呃逆，则是由热气壅滞郁结，气机不得通畅而形成的。轻症有和解法的适应证，重症有攻下法的适应证。《内经》说：如果有潮热且时时呃逆，给予小柴胡汤治疗的，这就是和解法的适应证。呃逆且腹部胀满，观察前后二阴，知道哪一部分不通利，通利它就可以痊愈，这就是攻下法的适应证。
伤寒病发展到呃逆阶段，病情已经极重了。不像口渴、烦躁等较轻缓的症状。例如太阳中风证，用火法强行发汗，导致阴阳气血都虚弱枯竭，身体干枯枯燥，只有头部出汗，至颈部而止，腹部胀满轻微气喘，口干咽喉溃烂，或者大便不通，时间久了会出现谵语，严重的甚至出现呃逆，这是说明病情到了极点。如果不排尿，腹部胀满加上呃逆的，属于不治之症，这是真脏气绝的表现。像这种情况，即使有神医的技术，面对这种脱绝的危候，又能如何施展手脚呢？
In the context of Cold Damage (Shanghan) disease, how should one elucidate the manifestation of hiccups (Yue)? Hiccups are commonly referred to as "ke ni" (coughing against the reverse). Qi-ni (a sensation of qi obstruction in the throat, pronounced like 'ye') is similar to hiccups. Qi-ni involves only a sensation of qi stagnation and blockage between the chest and throat, preventing downward flow, yet it produces no sound. In contrast, hiccups are characterized by audible "chi chi" sounds. Hiccups correspond to the Metal element in Five Elements theory; they arise because the Stomach is afflicted by disease. Both hiccups and Qi-ni are disorders of the Stomach, differing only in severity.
If deficiency-cold pathogens contend with each other, and water is administered to induce profuse sweating, the cold water will contend with the pathogenic cold. The patient will then develop Qi-ni, indicating that Stomach qi is deficient and exhausted. Following severe vomiting or purgation in Cold Damage disease, if the patient is extremely deficient and experiences profuse sweating, with external qi being constrained and depressed, administering water to induce further sweating may result in hiccups. This occurs because of coldness within the Stomach. Furthermore, if the Stomach is deficient and cold, unable to accept food, drinking water can trigger hiccups. From these observations, it is evident that both hiccups and Qi-ni are Stomach disorders.
The Classics state: If the foot-yang pulse (Duyang pulse) is floating, it indicates Qi-ni (qi obstruction); if the pulse is slippery, it indicates hiccups. These outcomes are due to medical error, specifically the mistake of treating a deficiency pattern as an excess pattern. Generally, after improper purgation, Stomach qi becomes deficient and rebels upward, leading to hiccups. The Classics also state: In patients with dampness, premature purgation leads to hiccups; attacking heat in a constitutionally deficient patient leads to hiccups; in Yangming disease, if the patient cannot eat and heat is attacked, hiccups will inevitably occur. All such cases result from hiccups caused by Stomach deficiency following purgation.
However, Qi-ni is caused by the contention of cold water and cold pathogens, and can be treated with Xiao Qing Long Tang (Minor Blue Dragon Decoction) with Mahuang removed and Fuzi added. Conversely, hiccups are formed by the congestion and depression of heat, preventing the free flow of qi. Mild cases have indications for harmonizing methods, while severe cases have indications for purging methods. The Classics state: If there is tidal fever accompanied by intermittent hiccups, Xiao Chai Hu Tang (Minor Bupleurum Decoction) is indicated, representing a harmonizing method. If hiccups are accompanied by abdominal fullness, one must examine the anterior and posterior orifices to determine which is obstructed; relieving the obstruction cures the condition, representing a purging method.
When Cold Damage disease progresses to hiccups, the illness has reached its extremity. It is not like mild symptoms such as thirst or irritability. For instance, in Taiyang wind-strike, if fire therapy is used to force sweating, yin and yang become both deficient and exhausted, the body becomes dry and withered, sweat appears only on the head stopping at the neck, there is abdominal fullness and slight panting, dry mouth and rotting throat, or constipation. Over time, delirium may occur, and in severe cases, hiccups appear, indicating the extremity of the disease. If urination ceases, abdominal fullness increases, and hiccups appear, it is untreatable, signifying the exhaustion of true qi. In such cases, even a divine physician would find it impossible to manage this critical state of collapse.