有声有物为呕，有物无声为吐，有声无物为哕。昔人以呕属阳明，吐属太阳，哕属少阳。哕即干呕。
东垣以三者俱属脾胃虚。洁古从三焦分别三因，上焦在胃口，主纳；中焦在中脘，主腐熟水谷；下焦在脐下，
主出而不纳。上焦吐者因于气，食已即吐，渴欲饮水，治当降气和中；中焦吐者因于积，或先痛后吐，或先
吐后痛，治当去积和气；下焦吐者因于寒，朝食暮吐，暮食朝吐，溺清便闭，治当通其闭，温其寒。后人又
分随食随吐，为呕，小半夏汤。食入乃吐，为暴吐，生姜橘皮汤。食已后吐，为呕吐，橘皮半夏汤、枳桔汤加
参、白芍、半夏。食久乃吐，为反胃，金花丸、理中汤。食在而吐者，为翻胃，紫沉丸。旦食暮吐，暮食朝吐，
下焦病，半夏生姜大黄汤。此从食下久暂，分上中下脘而治者也。古法，呕吐气壅，谷不得下，小半夏汤。
胃虚，谷气不行，呕而液伤，大半夏汤。胸满食谷欲呕，吴茱萸汤。心下痞，呕而肠鸣，半夏泻心汤。呕而
思水，饮停膈上，猪苓散。干呕哕，手足厥，橘皮汤。哕逆虚热，橘皮竹茹汤。哕逆虚寒，半夏干姜汤。干哕，
胃口有痰，二陈汤加姜汁。寒吐者，肢冷脉细，二陈汤加丁香、炮姜。诸药不效，红豆丸。热吐者，烦渴
脉洪，二陈汤加栀、连、竹茹、枇杷叶、姜汁、芦根汁。客寒犯胃，理中汤。肝火入胃，左金丸。由脾气
郁结，归脾汤加吴萸。由肝脾郁滞，香砂六君子汤。怒时饮食呕吐，胸满膈胀，关格不通，二陈汤加
青皮、木香。不效，加丁、沉、砂、蔻、藿、朴、曲、姜。由痰积者，遇寒辄发，蔻仁、丁香、砂仁、干姜、
半夏、陈皮。由食滞者，消导乃安，山楂、神曲、陈皮、枳壳、浓朴、砂仁、鸡金。先吐后泻，身热腹闷，
名曰漏气。因上焦伤风，邪气内着，麦门冬汤。二便不通，气逆不续，名曰走哺。因下焦实热，人参汤主之。
吐而中气久虚，必借谷食以和之。焦米、神曲、参、苓、苡米、谷芽、甘草、陈皮、姜、枣。吐而诸药不效，
必假重镇以坠之。灵砂丹、养正丹。病久胃虚呕吐者，六君子汤、比和饮、藿香安胃散。病后胃热烦呕者，竹
叶石膏汤加姜汁。呕苦邪在胆经，芩、连、吴萸、半夏、陈皮、茯苓、姜。吐酸责之肝脏，挟热者，左金丸加
竹茹、山栀、白蔻、生姜。挟寒者，左金丸加丁香、干姜、白术、沉香。呕清水者多停饮，二术二陈汤。吐涎
沫者以脾寒，六君子汤加益智、生姜，或理中汤加益智。吐蛔虫者，或由胃冷，理中汤加川椒、槟榔，下乌
梅丸。或由胃热，安蛔丸。或由寒热交错，乌梅丸。或由胃虚求食，温胃饮，理中汤。凡呕吐而心痛，当作
火治；口吐清水，当作虫治；心中如火，当作血虚治。
有声音且有呕吐物称为“呕”，仅有呕吐物而无声音称为“吐”，仅有声音而无呕吐物称为“哕”。古人认为，“呕”归属于阳明经，“吐”归属于太阳经，“哕”归属于少阳经。“哕”就是干呕。
李东垣认为这三种情况都归属于脾胃虚弱。张洁古则从三焦分别论述三种病因：上焦位于胃口，主要功能是受纳食物；中焦位于中脘，主要功能是腐熟水谷；下焦位于脐下，主要功能是排出废物而不受纳。上焦引起的呕吐是由于气机逆乱，进食后立即呕吐，口渴想喝水，治疗应当降气和胃；中焦引起的呕吐是由于积滞，或者先疼痛后呕吐，或者先呕吐后疼痛，治疗应当消除积滞、调和气机；下焦引起的呕吐是由于寒邪，早晨吃的饭晚上吐出，晚上吃的饭早晨吐出，小便清长、大便闭塞，治疗应当通利闭塞、温散寒邪。后人又区分随吃随吐的情况，称为“呕”，用小半夏汤。食物进入后才呕吐，称为“暴吐”，用生姜橘皮汤。吃完饭后才呕吐，称为“呕吐”，用橘皮半夏汤、枳桔汤加人参、白芍、半夏。吃很久之后才呕吐，称为“反胃”，用金花丸、理中汤。食物在胃中时就呕吐，称为“翻胃”，用紫沉丸。早上吃晚上吐，晚上吃早上吐，属于下焦病变，用半夏生姜大黄汤。这是根据食物停留时间的长短，区分上、中、下脘来进行治疗的古法。对于呕吐气机壅塞，谷物无法下咽的情况，用小半夏汤。胃气虚弱，谷气运行不畅，呕吐且津液受损的情况，用大半夏汤。胸中胀满，进食就想呕吐，用吴茱萸汤。心下痞塞，呕吐且肠鸣，用半夏泻心汤。呕吐且想喝水，是水饮停滞在膈上，用猪苓散。干呕或哕逆，手足厥冷，用橘皮汤。哕逆伴有虚热，用橘皮竹茹汤。哕逆伴有虚寒，用半夏干姜汤。干哕，是胃口有痰湿，用二陈汤加姜汁。寒性呕吐，表现为四肢冰冷、脉象细弱，用二陈汤加丁香、炮姜。各种药物无效时，用红豆丸。热性呕吐，表现为烦躁口渴、脉象洪大，用二陈汤加栀子、黄连、竹茹、枇杷叶、姜汁、芦根汁。外感寒邪侵犯胃腑，用理中汤。肝火侵入胃腑，用左金丸。由于脾气郁结所致，用归脾汤加吴茱萸。由于肝脾郁滞所致，用香砂六君子汤。愤怒时饮食导致呕吐，胸中胀满、膈部堵塞，关格不通，用二陈汤加青皮、木香。如果无效，再加丁香、沉香、砂仁、豆蔻、藿香、厚朴、神曲、生姜。由于痰积所致，遇寒冷就发作，用药包括蔻仁、丁香、砂仁、干姜、半夏、陈皮。由于食积停滞所致，需消食导滞才能安宁，用药包括山楂、神曲、陈皮、枳壳、厚朴、砂仁、鸡内金。先呕吐后腹泻，身体发热、腹部闷胀，名叫“漏气”。因上焦伤风，邪气内着，用麦门冬汤。大小便不通，气逆接续不上，名叫“走哺”。因下焦实热，用人参汤主治。呕吐且中气长期虚弱，必须借助谷食来调和。可用焦米、神曲、人参、茯苓、薏苡仁、谷芽、甘草、陈皮、生姜、大枣。呕吐且各种药物无效，必须借助重镇药物以坠降逆气。可用灵砂丹、养正丹。病程长久、胃虚导致的呕吐，用六君子汤、比和饮、藿香安胃散。病后胃热烦闷呕吐，用竹叶石膏汤加姜汁。呕吐苦水，说明邪气在胆经，用药包括黄芩、黄连、吴茱萸、半夏、陈皮、茯苓、生姜。吐酸水责之于肝脏，挟有热邪的，用左金丸加竹茹、山栀、白蔻、生姜。挟有寒邪的，用左金丸加丁香、干姜、白术、沉香。呕吐清水者多因停饮，用二术二陈汤（苍术、白术合二陈汤）。吐涎沫者因脾寒，用六君子汤加益智仁、生姜，或用理中汤加益智仁。吐蛔虫者，可能由于胃冷，用理中汤加川椒、槟榔，或服用乌梅丸。可能由于胃热，用安蛔丸。可能由于寒热错杂，用乌梅丸。可能由于胃虚求食，用温胃饮、理中汤。凡是呕吐伴有心痛，当作火证治疗；口吐清水，当作虫证治疗；心中感觉如火烧，当作血虚治疗。
Vomiting with sound and matter is termed "Ou" (Emesis); vomiting with matter but no sound is termed "Tu" (Regurgitation); vomiting with sound but no matter is termed "Yue" (Hiccough/Dry Heaving). Ancient practitioners associated Ou with the Yangming channel, Tu with the Taiyang channel, and Yue with the Shaoyang channel. Yue is equivalent to dry heaving.
Li Dongyuan considered all three conditions to belong to Spleen and Stomach deficiency. Zhang Jiegong distinguished the three causes according to the Sanjiao (Triple Burner): the Upper Jiao is located at the stomach opening and governs reception; the Middle Jiao is located at Zhongwan (CV12) and governs the decomposition and ripening of food and fluids; the Lower Jiao is located below the umbilicus and governs excretion without reception. Vomiting due to the Upper Jiao results from Qi rebellion, occurring immediately after eating, accompanied by thirst and desire for water; treatment should focus on descending Qi and harmonizing the middle. Vomiting due to the Middle Jiao results from accumulation, presenting as pain followed by vomiting or vomiting followed by pain; treatment should focus on removing accumulation and harmonizing Qi. Vomiting due to the Lower Jiao results from Cold, presenting as morning food vomited in the evening or evening food vomited in the morning, with clear urine and constipation; treatment should focus on unblocking obstruction and warming Cold.
Later practitioners further differentiated based on timing: vomiting immediately after eating is termed "Ou," treated with Xiaobanxia Tang (Minor Pinellia Decoction). Vomiting after food has entered is termed "Baotu" (Sudden Vomiting), treated with Shengjiang Jupi Tang (Fresh Ginger and Tangerine Peel Decoction). Vomiting after finishing a meal is termed "Outu" (Vomiting), treated with Jupi Banxia Tang (Tangerine Peel and Pinellia Decoction), or Zhijie Tang (Akebia and Citrus Decoction) added with Renshen (Ginseng), Baishao (White Peony Root), and Banxia (Pinellia Rhizome). Vomiting long after eating is termed "Fangwei" (Reverse Stomach), treated with Jinhua Wan (Golden Flower Pill) or Lizhong Tang (Regulate the Middle Decoction). Vomiting while food is still in the stomach is termed "Fangwei" (Overturning Stomach), treated with Zichen Wan (Purple Sink Pill). Morning food vomited in the evening, or evening food vomited in the morning, indicates pathology in the Lower Jiao, treated with Banxia Shengjiang Dahuang Tang (Pinellia, Fresh Ginger, and Rhubarb Decoction). This method treats based on the duration food remains in the Upper, Middle, and Lower Jiao.
According to ancient methods: For vomiting with Qi stagnation preventing grain intake, use Xiaobanxia Tang. For Stomach deficiency where Grain Qi fails to move, causing vomiting and fluid injury, use Dabanxia Tang (Major Pinellia Decoction). For chest fullness and desire to vomit after eating, use Wuzhuyu Tang (Evodia Decoction). For epigastric stuffiness with vomiting and borborygmus, use Banxia Xiexin Tang (Pinellia Decoction to Drain the Epigastrium). For vomiting with desire to drink, indicating fluid retention above the diaphragm, use Zhuling San (Polyporus Powder). For dry heaving and hiccough with cold extremities, use Jupi Tang (Tangerine Peel Decoction). For hiccough with deficient heat, use Jupi Zhuru Tang (Tangerine Peel and Bamboo Shavings Decoction). For hiccough with deficient cold, use Banxia Ganjiang Tang (Pinellia and Dried Ginger Decoction). For dry hiccough due to phlegm at the stomach opening, use Erchen Tang (Two Aged Substances Decoction) added with ginger juice.
For cold vomiting with cold limbs and fine pulse, use Erchen Tang added with Dingxiang (Clove) and Paojiang (Prepared Ginger). If various medicines fail, use Hongdou Wan (Red Bean Pill). For hot vomiting with irritability, thirst, and surging pulse, use Erchen Tang added with Zhizi (Gardenia), Lianhua (Coptis Rhizome), Zhuru (Bamboo Shavings), Pipaye (Loquat Leaf), ginger juice, and Lugenzhi (Reed Rhizome Juice). For external cold invading the Stomach, use Lizhong Tang. For Liver Fire entering the Stomach, use Zuojin Wan (Left Metal Pill). For spleen Qi depression and knotting, use Guipi Tang (Restore the Spleen Decoction) added with Wuzhuyu (Evodia Fruit). For Liver and Spleen depression and stagnation, use Xiangsha Liujunzi Tang (Costus and Amomum Six Gentlemen Decoction). For vomiting caused by diet during anger, with chest fullness and diaphragmatic distension leading to Guan Ge syndrome (Obstruction and Reversal), use Erchen Tang added with Qingpi (Green Tangerine Peel) and Muxiang (Aucklandia Root). If ineffective, add Dingxiang (Clove), Chenshen (Agarwood), Sharen (Amomum Fruit), Doukou (Cardamom), Huoxiang (Patchouli), Houpo (Magnolia Bark), Shenqu (Medicated Leaven), and Shengjiang (Fresh Ginger).
For cases due to phlegm accumulation, which flare up upon exposure to cold, use Doukou (Cardamom), Dingxiang (Clove), Sharen (Amomum Fruit), Ganjiang (Dried Ginger), Banxia (Pinellia Rhizome), Chenpi (Aged Tangerine Peel). For cases due to food stagnation, resolve with digestion-promoting herbs: ShanZha (Hawthorn Fruit), Shenqu (Medicated Leaven), Chenpi (Aged Tangerine Peel), Zhike (Immature Bitter Orange), Houpo (Magnolia Bark), Sharen (Amomum Fruit), Jijin (Chicken Gizzard Lining).
For vomiting followed by diarrhea, with body heat and abdominal stuffiness, it is named "Louqi" (Leaking Qi). Due to Wind attacking the Upper Jiao with pathogenic factors settling internally, use Maidong Tang (Ophiopogon Decoction). For unblocked urination and defecation with rebellious Qi failing to continue, it is named "Zoubu" (Running Nourishment). Due to Excess Heat in the Lower Jiao, treat with Renshen Tang (Ginseng Decoction).
For vomiting with long-term deficiency of Middle Qi, nourish with grain foods: Jiaomi (Scorched Rice), Shenqu (Medicated Leaven), Renshen (Ginseng), Fuling (Poria), Yimi (Coix Seed), Guya (Grain Sprout), Gancao (Licorice Root), Chenpi (Aged Tangerine Peel), Shengjiang (Fresh Ginger), Zao (Jujube). For vomiting where all medicines fail, use heavy sedatives to descend rebellious Qi: Lingsha Dan (Cinnabar Elixir) or Yangzheng Dan (Nourishing Righteousness Elixir).
For chronic vomiting due to Stomach deficiency, use Liujunzi Tang (Six Gentlemen Decoction), Bihe Yin (Harmonizing Drink), or Huoxiang Anwei San (Patchouli Stomach-Calming Powder). For post-illness vomiting due to Stomach heat and irritability, use Zhuye Shigao Tang (Leaf of Bamboo and Gypsum Decoction) added with ginger juice.
For bitter vomiting, the pathogen is in the Gallbladder channel: Huangqin (Scutellaria Root), Huanglian (Coptis Rhizome), Wuzhuyu (Evodia Fruit), Banxia (Pinellia Rhizome), Chenpi (Aged Tangerine Peel), Fuling (Poria), Shengjiang (Fresh Ginger). For sour regurgitation, blame the Liver: if accompanied by heat, use Zuojin Wan (Left Metal Pill) added with Zhuru (Bamboo Shavings), Shanzhi (Gardenia), Baikou (White Cardamom), and Shengjiang (Fresh Ginger); if accompanied by cold, use Zuojin Wan added with Dingxiang (Clove), Ganjiang (Dried Ginger), Baizhu (Atractylodes Macrocephala Rhizome), and Chenxiang (Agarwood). For vomiting clear fluid, there is likely fluid retention: use Ershui Erchen Tang (Two Atractylodes and Two Aged Substances Decoction). For spitting saliva and foam, blame Spleen Cold: use Liujunzi Tang (Six Gentlemen Decoction) added with Yizhi (Alpinia Oxyphylla Fruit) and Shengjiang (Fresh Ginger), or Lizhong Tang (Regulate the Middle Decoction) added with Yizhi (Alpinia Oxyphylla Fruit).
For vomiting roundworms: if due to Stomach Cold, use Lizhong Tang (Regulate the Middle Decoction) added with Chuanjiao (Sichuan Pepper) and Binglang (Areca Seed), or administer Wu Mei Wan (Mume Pill); if due to Stomach Heat, use Anhui Wan (Calming Worm Pill); if due to mixed Cold and Heat, use Wu Mei Wan (Mume Pill); if due to Stomach deficiency seeking food, use Wenwei Yin (Warm Stomach Drink) or Lizhong Tang (Regulate the Middle Decoction).
Generally, for vomiting accompanied by heart pain, treat as Fire; for spitting clear fluid, treat as Worms; for a sensation of fire in the heart, treat as Blood Deficiency.