《内经》所谓噫，即今所谓嗳气也。宣明五气论，以心为噫。痹论，以心痹者，
脉不通，烦则心下鼓，暴上气而喘，嗌干善噫。至真大要论，以太阳司天，少阴之
复，皆为哕噫。四时刺逆从论，刺中心一日死，其动为噫。阴阳别论，二阳一阴发
病，主惊骇背痛，善噫善欠，名曰风厥。脉解，太阴所谓上走心为噫者，阴盛而上
走于阳明，阳明络属心，故曰上走心为噫也。此乃噫从心出者也。厥阴在泉，腹胀
善噫，得后与气，则快然如衰。玉版论，太阴终者，善噫。《灵枢》云∶足太阴是动
病，腹胀善噫。又云∶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。（卫出上焦。）又云∶上焦不归者，噫而酢酸。（不
归，不至也。上焦之气不至其部，则物不能传化，故噫而吞酸。）由是观之，噫者是火土
之气郁而不得发，故噫而出。王注解心为噫之义，象火炎上，烟随焰出。如痰闭膈间，中气不得
伸而嗳者，亦土气内郁也。仲景云∶痞而噫，旋复代赭汤主之。《本事方》心下蓄积，痞
闷或作痛，多噫败卵气，枳壳散主之。丹溪云∶胃中有实火，膈上有稠痰，故成嗳气。用
二陈汤加香附、栀子仁、黄连、苏子、前胡、青黛、栝蒌，或丸或汤服之。
【诊】寸口脉弱而缓，弱者阳气不足，缓者胃气有余，噫而吞酸，食卒不下，
气填于膈上。寸脉紧，寒之实也。寒在上焦，胸中必满而噫。趺阳脉微而涩，微无
胃气，涩即伤脾，寒在膈而反下之，寒积不消，胃微脾伤，谷气不行，食已自噫。
寒在胸膈，上虚下实，谷气不通，为闭塞之病。趺阳脉微涩，及寸脉紧而噫者，皆
属寒。太阴终者，腹胀闭，噫气呕逆。
《内经》中所说的“噫”，就是现在所说的嗳气。《素问·宣明五气论》认为，心主噫。《素问·痹论》指出，患心痹的人，脉道不通，心烦时感觉心下悸动如鼓，突然气逆上冲而喘息，咽喉干燥，经常嗳气。《素问·至真要大论》提到，当太阳司天，少阴之气复返时，都会出现呃逆和嗳气。《素问·四时刺逆从论》说，针刺误中心脏，一天后死亡，其症状表现为嗳气。《素问·阴阳别论》记载，二阳（胃与大肠）与一阴（肝）同时发病，主要症状为惊骇、背痛，经常嗳气和呵欠，这种病名叫风厥。《素问·脉解篇》解释，太阴经所说的“气上走于心导致嗳气”，是因为阴气过盛而上行侵犯阳明经，阳明经络属心脏，所以说气上走于心导致嗳气。这是说嗳气是从心发出的。《素问·厥阴在泉》提到，厥阴风木在泉之年，腹部胀满且经常嗳气，大小便通畅或排气后，症状就会减轻。《素问·玉版论要》说，太阴经气终绝时，会经常嗳气。《灵枢》中说：足太阴脾经发生病变，会出现腹部胀满且经常嗳气。又说：寒气客居于胃中，厥逆之气从下向上散漫，再出于胃，所以形成嗳气。张仲景认为，上焦接受了中焦的气但未能调和，不能消化食物，因此能够嗳气。（卫气出于上焦。）又说：如果上焦之气不回归本位，就会出现嗳气并伴有吞酸。（不归，即不到达。上焦之气不能到达其部位，则食物不能传化，所以嗳气并吞酸。）由此看来，嗳气是火气和土气郁结而不能发散，所以通过嗳气排出。王冰注解“心为噫”的含义，形象地比喻为火炎上烧，烟随火焰冒出。如痰浊闭塞胸膈之间，中焦之气不得舒展而嗳气的，也是土气内部郁结所致。张仲景说：痞证兼有嗳气，用旋覆代赭汤主治。《济生方》（此处指《杨氏家藏方》或《本事方》，原文作《本事方》，通常指沈括《苏沈良方》或陈无择《三因方》等，此处依原文译）中提到，心下积聚，痞闷或疼痛，多嗳出腐败卵臭的气味，用枳壳散主治。朱丹溪说：胃中有实火，膈上有稠痰，所以形成嗳气。使用二陈汤加香附、栀子仁、黄连、苏子、前胡、青黛、栝蒌，制成丸剂或汤剂服用。
【诊法】寸口脉弱而缓，弱表示阳气不足，缓表示胃气有余，表现为嗳气并吞酸，食物突然难以下咽，气堵塞在膈上。寸脉紧，是寒邪实证的表现。寒邪在上焦，胸部必定胀满且嗳气。趺阳脉微而涩，微表示没有胃气，涩表示损伤了脾，如果在膈部有寒邪反而使用攻下法，会导致寒积不消，胃气微弱脾气受伤，谷气运行不畅，进食后即自发性嗳气。寒邪在胸膈，上虚下实，谷气不通，属于闭塞的病证。趺阳脉微涩，以及寸脉紧且伴有嗳气的，都属于寒证。太阴经气终绝时，腹部胀满闭塞，嗳气且呕吐逆气。
The "yi" (belching) mentioned in the *Neijing* (*Inner Canon*) is what is now called eructation. The *Suwen: Xuanming Wuqi Lun* states that the Heart governs belching. The *Suwen: Bi Lun* indicates that in cases of Heart Bi (obstruction syndrome), the vessels are unpatent; when vexation occurs, there is a sensation of palpitation like drumbeats in the epigastrium, sudden upward rushing of Qi leading to panting, dryness of the throat, and frequent belching. The *Suwen: Zhihen Dayao Lun* mentions that when Taiyang governs the year and Shaoyin Qi retaliates, both conditions manifest as hiccups and belching. The *Suwen: Sishi Cini Cong Lun* states that if the heart is accidentally punctured during acupuncture, death ensues within one day, with the symptom being belching. The *Suwen: Yin Yang Bie Lun* records that when the Two Yang (Stomach and Large Intestine) and One Yin (Liver) diseases occur simultaneously, the main symptoms include fright, back pain, frequent belching, and yawning; this condition is named Feng Jue (Wind Jue). The *Suwen: Maijie* explains that what the Taiyin meridian refers to as "Qi moving upward to the heart causing belching" occurs because Yin Qi is excessive and moves upward to invade the Yangming meridian; since the Yangming meridian connects to and belongs to the Heart, it is said that Qi moves upward to the heart causing belching. This indicates that belching originates from the Heart. The *Suwen: Jueyin Zaiquan* notes that in years when Jueyin Wind Wood governs below, abdominal distension and frequent belching occur; after defecation or passage of flatus, the patient feels relieved and symptoms subside. The *Suwen: Yuban Lunyao* states that when Taiyin Qi reaches its end, there is frequent belching. The *Lingshu* says: When the Foot-Taiyin Spleen meridian is affected, abdominal distension and frequent belching occur. It also states: When cold pathogens lodge in the Stomach, rebellious Qi scatters upward from below and re-emerges from the Stomach, thus forming belching. Zhang Zhongjing posits that when the Upper Jiao receives Qi from the Middle Jiao but fails to harmonize it, digestion is impaired, resulting in belching. (Wei Qi emerges from the Upper Jiao.) He further states: If the Qi of the Upper Jiao does not return to its proper position, belching accompanied by acid regurgitation occurs. ("Not returning" means failing to arrive. When the Qi of the Upper Jiao fails to reach its region, food cannot be transmitted and transformed, hence belching and acid regurgitation.) From this, we can see that belching results from the stagnation and failure to disperse of Fire and Earth Qi, which is expelled through belching. Wang Bing’s annotation on the meaning of "Heart governs belching" uses the metaphor of fire flaming upward, with smoke following the flames. For instance, when phlegm turbidity obstructs the chest and diaphragm, preventing Middle Jiao Qi from extending freely, resulting in belching, this is also due to the internal stagnation of Earth Qi. Zhang Zhongjing stated: In cases of Pi (fullness obstruction) syndrome accompanied by belching, Xu Fu Dai Zhe Tang (Inula and Hematite Decoction) should be administered. The *Benshi Fang* describes accumulation in the epigastrium, fullness and oppression or pain, often with belching smelling of rotten eggs; this is treated with Zhi Qiao San (Immature Bitter Orange Powder). Zhu Danxi stated: Excess Fire in the Stomach and thick phlegm above the diaphragm lead to eructation. Er Chen Tang (Two-Cured Decoction) is used with added Xiang Fu (Cyperus Rhizome), Zhi Zi Ren (Gardenia Seed), Huang Lian (Coptis Rhizome), Su Zi (Perilla Fruit), Qian Hu (Peucedani Radix), Qing Dai (Indigo Naturalis), and Gua Lou (Trichosanthes Fruit), administered as either pills or decoction.
[Diagnosis] If the Cun Kou pulse is weak and slow, weakness indicates insufficiency of Yang Qi, while slowness indicates excess Stomach Qi; symptoms include belching with acid regurgitation, sudden inability to swallow food, and Qi blocking above the diaphragm. A tight pulse at the Cun position indicates an excess Cold pathogen. If Cold is located in the Upper Jiao, the chest will certainly be full and accompanied by belching. A faint and choppy pulse at the Zu Yang position indicates absence of Stomach Qi (faint) and injury to the Spleen (choppy); if purgatives are incorrectly used for Cold in the diaphragm, Cold accumulation persists, Stomach Qi becomes weak, Spleen function is damaged, Grain Qi fails to circulate, and spontaneous belching occurs after eating. Cold in the chest and diaphragm, characterized by deficiency above and excess below, with blocked Grain Qi, constitutes an obstruction syndrome. Both a faint and choppy Zu Yang pulse and a tight Cun pulse with belching belong to Cold syndromes. When Taiyin Qi reaches its end, abdominal distension and closure occur, along with belching and vomiting/rebellious Qi.