大法春宜吐凡用吐汤中病即止不必尽剂也病如桂枝证头不痛项不强寸脉微浮胸中痞硬气上撞咽喉不得息者此为有
寒当吐之（一云此以内有久痰宜吐之）病胸上诸实（一作寒）胸中郁郁而痛不能食欲使人按之而反有涎唾下利日十余行
其脉反迟寸口脉微滑此可吐之吐之利则止少阴病饮食入口则吐心中 欲吐复不能吐者宜吐之又宿食在上脘手足逆冷
脉乍结以客气在胸中心下满而烦欲食不能食者病在胸中皆当吐之
吴 凡病在膈上者脉大胸满多痰者食在胃口脉滑者俱宜吐之华佗谓伤寒三四日邪在胸中者宜吐之凡吐用瓜蒂散
或淡盐汤或温茶汤与之如人弱者以人参芦汤吐之亦可若痰多者以二陈汤一瓯乘热与之以指探喉中即吐也凡老人怯弱与病
劳内伤虚人并妇人胎前产后血虚脉弱小者皆不可吐凡药发吐者如防风桔梗山栀只有一味煎汤温服之则吐盖误吐则损人
上焦元气为患非轻可不慎哉
太阳病当恶寒发热今自汗出反不恶寒发热关上脉细数者以医吐之过也若得病一二日吐之者腹中饥口不能食三四日
吐之者不喜糜粥欲食冷食朝食暮吐以医吐之所致也此为小逆太阳病吐之但太阳病当恶寒今反不恶寒不欲近衣者此为吐
之内烦也少阴病饮食入口则吐心中 欲吐复不能吐始得之手足寒脉弦迟者此胸中实不可下也若膈上有寒饮干呕者不
可吐也当温之少阳中风两耳无所闻目赤胸中满而烦者不可吐下吐下则悸而惊四肢厥虚家新产脉微皆不可吐
治疗大法：春季适宜使用吐法。凡是使用催吐汤剂，只要病邪去除就应停止，不必服完全部剂量。如果病症表现类似桂枝证（太阳中风表虚证），但头部不痛、项部不强硬，寸脉微浮，胸中痞塞坚硬，气逆冲撞咽喉导致呼吸不畅，这是体内有寒邪，应当使用吐法。（另一种说法认为这是因为体内素有久痰，适宜用吐法）。患有胸部各种实邪阻滞，胸中郁闷疼痛，不能进食，让人按压反而流出涎唾，腹泻一天十多次，脉象反而迟缓，寸口脉微滑的，可以使用吐法；吐后腹泻就会停止。少阴病，饮食入口即吐，心中烦闷想要呕吐却又吐不出来，适宜使用吐法。又有宿食停留在上脘，手足逆冷，脉象突然结滞，因为客气（邪气）在胸中，心下痞满且烦躁，想吃却吃不下，病位在胸中，都应当使用吐法。
吴氏指出：凡是病位在膈膜以上，脉象大，胸满多痰的；或者食物停滞在胃口，脉象滑的，都适宜使用吐法。华佗说：伤寒病经过三四天，邪气在胸中的，适宜使用吐法。凡是使用吐法，可用瓜蒂散，或淡盐水，或温茶送服。如果病人身体虚弱，用人参芦煎汤催吐也可以。如果痰多的，用二陈汤一杯趁热服用，用手指探喉即可引发呕吐。凡是老年人怯弱，以及患虚劳内伤的虚人，还有妇女怀孕前和产后血虚、脉象弱小的，都不可使用吐法。凡是用药引起呕吐的，如防风、桔梗、山栀，只用其中一味煎汤温服，就能引发呕吐。大概是因为误用吐法会损伤人体上焦元气，造成的危害不小，怎能不谨慎呢？
太阳病应当恶寒发热，现在患者自汗出，反而不恶寒、不发热，关上脉细数，这是因为医生误用吐法造成的过失。如果得病一两天就用吐法，会导致腹中饥饿却口不能食；得病三四天用吐法，会导致不喜欢喝稀粥，想吃冷食，早晨吃晚上吐，这都是因为医生误用吐法所致。这属于轻微的逆证。太阳病如果用吐法，但太阳病本当恶寒，现在反而不恶寒、不想穿衣，这是因为吐法导致的内部烦热。少阴病，饮食入口即吐，心中烦闷想要呕吐却又吐不出来，刚发病时手足寒冷，脉象弦迟，这是胸中有实邪，不可使用下法。如果膈上有寒饮导致干呕的，也不可使用吐法，应当温补。少阳中风，两耳听不见，目赤，胸中满闷且烦躁的，不可使用吐法或下法；若误用吐下，则会出现心悸和惊悸。四肢厥冷的虚家，以及新产妇人，脉象微弱的，都不可使用吐法。
General Principle: In spring, the emetic method is suitable. When using an emetic decoction, stop as soon as the pathogenic factor is eliminated; there is no need to consume the entire dose. If the symptoms resemble those of Guizhi Tang (Cinnamon Twig Decoction) syndrome—specifically Taiyang Wind-Strike deficiency syndrome—but without headache or stiffness of the neck, with a slightly floating pulse at the Cun position, chest oppression and hardness, Qi rebelling against the throat causing dyspnea, this indicates cold in the interior and should be treated with emesis. (Another view suggests this is due to long-standing phlegm in the interior, making emesis appropriate.) For conditions involving various excess pathogens in the upper chest, with stifling pain in the chest, inability to eat, salivation upon palpation, and diarrhea occurring more than ten times a day, where the pulse is surprisingly slow and the Cun position pulse is slightly slippery, emesis may be used; the diarrhea will cease after vomiting. In Shaoyin disease, if food is vomited immediately upon entering the mouth, accompanied by central irritability and a desire to vomit but inability to do so, emesis is indicated. Similarly, for retained food in the upper Jiao presenting with reversed coldness of the hands and feet, intermittent knotted pulse, rebellious Qi in the chest, epigastric fullness and irritability, and an inability to eat despite hunger, where the pathology is located in the chest, emesis is indicated.
Wu stated that for diseases located above the diaphragm with a large pulse, chest fullness, and abundant phlegm; or for food stagnation at the stomach opening with a slippery pulse, emesis is suitable. Hua Tuo stated that for Shanghan (Cold Damage) disease on the third or fourth day, when the pathogen is in the chest, emesis is indicated. Generally, for emetic treatment, Gengti San (Melon Seed Powder) can be used, or light salt water, or warm tea. For weak patients, Ren Shen Lu Tang (Ginseng Rhizome Decoction) can be used to induce vomiting. If there is excessive phlegm, Er Chen Tang (Two-Cured Decoction) taken warm in one cup, followed by stimulating the throat with a finger, will induce vomiting. Emetic methods are contraindicated for elderly individuals with frailty, patients with Xu Lao (Consumption and Overstrain) and internal injury constituting deficiency, and women during pregnancy or postpartum with blood deficiency and weak pulses. Medicines such as Fang Feng (Saposhnikovia Root), Jie Geng (Platycodon Root), and Shan Zhi (Gardenia Fruit), when decocted alone and taken warm, can induce vomiting. This is because improper use of emesis damages the Yuan Qi (Original Qi) of the Upper Jiao, causing significant harm; therefore, caution is essential.
In Taiyang disease, aversion to cold and fever are expected. However, if the patient has spontaneous sweating and lacks aversion to cold or fever, with a fine and rapid pulse at the Guan position, this is an error caused by the physician's inappropriate use of emesis. If emesis is used within one or two days of contracting the disease, it results in abdominal hunger but an inability to eat. If used on the third or fourth day, it leads to a dislike for millet gruel, a craving for cold food, and regurgitation of morning food by evening; these are consequences of the physician's erroneous emesis. This constitutes a minor adverse reaction. If emesis is applied to Taiyang disease, but the patient who should have aversion to cold instead shows no aversion to cold and dislikes wearing clothes, this indicates internal irritability caused by the emetic procedure. In Shaoyin disease, if food is vomited immediately upon entry, with central irritability and a desire to vomit but inability to do so, accompanied by cold extremities and a wiry, slow pulse at onset, this indicates excess in the chest; purgation is contraindicated. If dry heaving is caused by cold-fluid retention above the diaphragm, emesis is also contraindicated; warming therapy is required. In Shaoyang Wind-Strike, characterized by deafness, red eyes, chest fullness, and irritability, neither emesis nor purgation should be used; improper application leads to palpitations and fright. Patients with cold extremities and deficiency, as well as postpartum women with faint pulses, are all contraindicated for emesis.