〔《活》〕半夏桂枝甘草汤治伏气之病，谓非时有暴寒中人，伏气于少阴经，始不觉病，旬月乃发，脉更微弱。
先发咽痛似伤寒，非喉痹之病，必下利，始用半夏桂枝甘草汤主之，此病只二日便瘥，古方谓之肾伤
寒也，次用四逆主之。
半夏桂枝甘草汤
半夏（汤洗） 甘草（炙） 桂心（各等分）
上 咀，每服四钱，水煎候冷，少少细呷之。（即仲景半夏散及汤，但药 咀耳。）
腹满时痛而吐者，太阴病。论见腹满。（《活人》云∶理中汤主之。）
少阴病，欲吐不吐，心烦，但欲寐，自利而渴。（论见下利。《活人》云∶四逆汤主之。）少阴病，
饮食入口则吐，心中温温欲吐，复不能吐，始得之手足寒，脉弦迟者，此胸中实，不可下也，当吐之。
若膈有寒饮，干呕者，不可吐也，急温之，宜四逆汤。少阴病，但欲卧，不烦而吐，五日变自利，
烦躁不得寐者死。（论见但欲寐。）
腹痛欲呕吐者，宜黄连汤。病解后虚羸少气欲吐者，宜竹叶石膏汤。
干呕吐涎沫头痛者，宜吴茱萸汤。
吴茱萸（汤泡洗，一两半） 人参（三分） 生姜（一两半） 大枣（三枚）
上 咀，水煎去渣，分二服。
发热，渴欲饮水，水入则吐者，宜五苓散。（论见厥。）
伤寒本自寒下，医复吐下之，寒格更逆吐下。若食入口即吐，干姜黄连黄芩人参汤主之。
干姜 黄连 黄芩 人参（各等分）
上 咀，水煎温服。
太阳病吐后，汗出不恶寒，发热，关脉细数，欲食冷食，朝食暮吐，此为小逆。（论见发热。）
病患脉数为热，当消谷引食而反吐者，此因发汗，令阳气微，膈气虚，脉乃数也。数而客热者，不能消谷，
以胃中虚冷故也。凡服桂枝汤而吐者，必吐脓血也。（注云∶内热者，服桂枝汤则吐，如酒客之类是也。）
吐厥逆者，甘姜。
【《活人书》】半夏桂枝甘草汤治疗伏气病，所谓非时之暴寒侵袭人体，邪气潜伏于少阴经，起初不觉有病，经过一个月左右才发作，脉象更加微弱。
起初出现咽痛，类似伤寒，但不是喉痹病，必定伴有下利，此时才使用半夏桂枝甘草汤主治，此病若仅两天即可痊愈，古方称之为肾伤寒，随后使用四逆汤主治。
半夏桂枝甘草汤
半夏（用汤洗） 甘草（炙） 桂心（各等分）
以上药物切碎，每次服用四钱，加水煎煮，待药液冷却后，少量细细呷服。（即张仲景的半夏散及汤，只是将药物切碎而非捣碎。）
腹部胀满且时而疼痛并伴有呕吐的，是太阴病。相关论述见“腹满”条。（《活人书》说：用理中汤主治。）
少阴病，想吐却吐不出来，心烦，只想睡觉，自发性腹泻且口渴。（相关论述见“下利”条。《活人书》说：用四逆汤主治。）
少阴病，饮食入口就吐，心中泛泛欲吐却又吐不出，刚发病时手足寒冷，脉象弦而迟缓的，这是胸中有实邪，不可用泻下法，应当用涌吐法。
如果膈间有寒饮，导致干呕的，不可用涌吐法，应当紧急温阳，适宜用四逆汤。
少阴病，只想躺卧，不心烦但呕吐，五天后变为自发性腹泻，烦躁不得睡眠的，预后不良属死证。（相关论述见“但欲寐”条。）
腹痛想要呕吐的，适宜用黄连汤。病愈后身体虚弱消瘦、气息短少想吐的，适宜用竹叶石膏汤。
干呕、吐出清稀涎沫并伴有头痛的，适宜用吴茱萸汤。
吴茱萸（用汤泡洗，一两半） 人参（三分） 生姜（一两半） 大枣（三枚）
以上药物切碎，加水煎煮去渣，分两次服用。
发热，口渴想喝水，水喝进去就吐出来的，适宜用五苓散。（相关论述见“厥”条。）
伤寒本来就有寒性下利，医生又误用吐法和下法，导致寒邪格拒，反而加重了呕吐和下利。如果食物入口立即吐出，用干姜黄连黄芩人参汤主治。
干姜 黄连 黄芩 人参（各等分）
以上药物切碎，加水煎煮，温服。
太阳病在呕吐之后，出汗且不恶寒，发热，关脉细数，想吃冷食，早上吃晚上吐，这属于小逆证。（相关论述见“发热”条。）
病人脉数表示有热，应当消化食物并食欲旺盛，反而呕吐的，这是因为发汗导致阳气微弱，膈气虚弱，脉象才表现为数。脉数而有客热，不能消化食物，是因为胃中虚冷的缘故。凡是服用桂枝汤后发生呕吐的，必定会吐出脓血。（注解说：体内有热的人，服用桂枝汤就会呕吐，如常饮酒之人就是此类。）
因呕吐导致四肢厥逆的，用甘姜（治之）。
[From *Liu Ren Shu*] Banxia Guizhi Gancao Tang (Pinellia, Cinnamon Twig, and Licorice Decoction) treats Fuqi disease (latent qi disease). This refers to sudden cold invading the body out of season, with pathogenic qi lying latent in the Shaoyin meridian (Lesser Yin channel). Initially, no illness is felt; after about a month, it manifests with a pulse that is even more weak and faint.
Initially, there is sore throat resembling Taiyang cold damage (Shanghan), but it is not Hou Bi (sore throat obstruction). There must be diarrhea. At this point, Banxia Guizhi Gancao Tang should be used as the primary treatment. If this disease resolves within two days, ancient formulas call it Kidney Cold Damage (Shen Shang Han). Subsequently, Sini Tang (Frigid Extremities Decoction) should be used.
Banxia Guizhi Gancao Tang (Pinellia, Cinnamon Twig, and Licorice Decoction)
Banxia (Pinelliae Rhizoma, washed with decoction)
Gancao (Glycyrrhizae Radix et Rhizoma, honey-fried)
Guixin (Cinnamomi Cortex, equal parts)
Chop the above herbs. Take 4 qian per dose, decoct in water, wait for it to cool, and sip slowly in small amounts. (This is essentially Zhang Zhongjing's Banxia San Ji Tang [Pinellia Powder and Decoction], except the herbs are chopped rather than crushed.)
Abdominal fullness, intermittent pain, and vomiting indicate Taiyin disease (Greater Yin disease). See the discussion under "Abdominal Fullness". (*Liu Ren Shu* states: Treat with Lizhong Tang [Regulate the Middle Decoction].)
Shaoyin disease (Lesser Yin disease) characterized by the desire to vomit but inability to do so, irritability, only wanting to sleep, spontaneous diarrhea, and thirst. (See the discussion under "Diarrhea". *Liu Ren Shu* states: Treat with Sini Tang [Frigid Extremities Decoction].)
Shaoyin disease where food entering the mouth causes immediate vomiting, a sensation of nausea in the heart without actual vomiting, cold hands and feet at the onset, and a string-taut and slow pulse indicates excess in the chest. Purging is contraindicated; emesis (vomiting therapy) should be induced.
If there is cold-fluid retention in the diaphragm causing dry heaving, emesis is contraindicated. Urgent warming is required; Sini Tang (Frigid Extremities Decoction) is appropriate.
In Shaoyin disease, if the patient only wants to lie down, has no irritability but vomits, and after five days develops spontaneous diarrhea, irritability, and insomnia, the prognosis is fatal. (See the discussion under "Only Wanting to Sleep".)
For abdominal pain with the desire to vomit, Huanglian Tang (Coptis Decoction) is appropriate. For post-illness debility, emaciation, shortness of breath, and desire to vomit, Zhuyegao Shi Tang (Bamboo Leaf and Gypsum Decoction) is appropriate.
For dry heaving, spitting of clear saliva, and headache, Wuzhuyu Tang (Evodia Decoction) is appropriate.
Wuzhuyu Tang (Evodia Decoction)
Wuzhuyu (Evodiae Fructus, soaked and washed in decoction, 1.5 liang)
Renshen (Ginseng Radix et Rhizoma, 3 fen)
Shengjiang (Zingiberis Rhizoma Recens, 1.5 liang)
Dazao (Jujubae Fructus, 3 pieces)
Chop the above herbs, decoct in water, remove the dregs, and divide into two doses.
For fever, thirst with desire to drink water, and vomiting immediately after drinking, Wuling San (Five-Ingredient Powder with Poria) is appropriate. (See the discussion under "Jue" [Cold Extremities].)
In Shanghan (Cold Damage), if there was originally cold-type diarrhea, and the physician incorrectly applied emesis and purgation, cold obstruction leads to aggravated vomiting and diarrhea. If food is vomited immediately upon entering the mouth, Ganjiang Huanglian Huangqin Renshen Tang (Dried Ginger, Coptis, Scutellaria, and Ginseng Decoction) is indicated.
Ganjiang (Zingiberis Rhizoma)
Huanglian (Coptidis Rhizoma)
Huangqin (Scutellariae Radix)
Renshen (Ginseng Radix et Rhizoma) (Equal parts)
Chop the above herbs, decoct in water, and take warm.
After vomiting in Taiyang disease (Greater Yang disease), if sweating occurs without aversion to cold, accompanied by fever, a fine and rapid guan pulse, desire for cold food, and morning intake with evening vomiting, this is considered a minor deviation (Xiao Ni). (See the discussion under "Fever".)
A rapid pulse indicates heat, which should lead to digestion of food and increased appetite. If vomiting occurs instead, it is because sweating caused slight yang deficiency and empty qi in the diaphragm, resulting in a rapid pulse. A rapid pulse with exogenous heat cannot digest food due to cold deficiency in the stomach. Generally, those who vomit after taking Guizhi Tang (Cinnamon Twig Decoction) will vomit pus and blood. (Note: Those with internal heat, such as habitual drinkers, will vomit after taking Guizhi Tang.)
For vomiting leading to Jue Ni (cold extremities reversal), use Gan Jiang (Dried Ginger).