经曰∶其有邪者，渍形以为汗。其在皮者，汗而发之。又曰∶体若燔炭，汗出而散。又
曰∶未满三日，可汗而已，举是四者，盖其在表不可使之深入，要当以汗去之。然汗有起于
过用而为常者，有忽于畏护而为患者，有汗之太过。遂漏不止者，阳气虚而表弱也。有汗之
不及者，则邪气复与正气交争，昔人论汗出不彻，因转属阳明、是也。如此则阴阳不得平均
，营卫不得调和矣。虽然，病有表里，汗有宜否，若不须汗而强与汗之者，将耗其津液。须
汗而不与汗之者，使邪气深而经络传变，势如风雨，何可当也。载诸方籍其类多矣，大概可
汗之证，则身热脉浮，太阳与阳明证是也。其不可汗之证，在经则少阳与厥阴，在病则厥与
逆，以至血衄疮淋之属，皆为不可汗。或邪气在表而脉沉迟者，虽汗之亦不能解矣，非特此
也。太阳固可汗也，有因发汗而为痉者，脉浮体痛，固当以汗解也。假令尺中脉迟，则亦不
可汗，是又不可不知也。
三焦为决渍之官，升降冲气而不息者也。病在胸中，上焦气壅，必因其高而越之，所以
去邪实而导正气也。况上脘之病，上而未下，务在速去，不涌而出之，则深入肠胃，播传诸
经。可胜治哉，故若宿食有可吐者，未入于肠胃者也，痰疟有可吐者，停蓄于胸膈者也。食
毒忤气可吐者，恐其邪久而滋甚也。肺痈酒疸可吐者，为其胸满而心闷也，大抵胸中邪实，
攻之不能散，达之不能通，必以酸苦之药涌之。故得胃气不伤而病易以愈，古人大法，春宜
吐，盖以春气高而在上，上实下虚，其治宜高故也，又以寸口脉浮之类可吐。盖以病在膈上
。气不下通，其脉浮故也。审此二者，则吐法之用，不可妄施。
《黄帝内经》说：对于有外邪侵袭的病症，通过浸渍身体来发汗。病邪在皮肤层面的，应当用发汗的方法将其发散出去。又说：身体发热像燃烧的炭火一样，出汗后热势就会消散。还说：病程未满三天，可以通过发汗使疾病痊愈。列举这四种情况，大概是因为病邪在体表，不能让它深入体内，关键在于通过发汗来祛除它。
然而，发汗也有因过度使用而成为常规习惯的情况，也有因为疏忽防护而导致病变的情况，还有因发汗太过导致汗漏不止的，这是阳气虚弱、肌表不固的表现。也有因发汗不足的，导致邪气再次与正气交争，古人论述汗出不彻底，因而转属阳明病，说的就是这种情况。这样就会导致阴阳失去平衡，营卫之气无法调和。
虽然如此，疾病有表证和里证的区别，发汗也有适宜和不适宜之分。如果不需要发汗却强行发汗，将会耗伤津液；如果需要发汗却不给予发汗治疗，会使邪气深入并发生经络传变，其势头如风雨般猛烈，谁能抵挡得住呢？记载于各方籍中的案例很多了，大致来说，适宜发汗的证候，表现为身体发热、脉象浮，这是太阳病和阳明病的表现。不适宜发汗的证候，在经络方面是少阳经和厥阴经的病，在疾病方面是厥证和逆证，以及鼻出血、疮疡、淋证等类别，都属于不可发汗的范围。或者邪气虽然在体表但脉象沉迟的，即使发汗也不能解除，不仅仅是这些情况。太阳病固然可以发汗，但也有因发汗不当而转为痉病的，虽然脉浮、身体疼痛，本应当用发汗法解除，但如果尺部脉象迟缓，也不可以发汗，这也是必须知道的。
三焦是决渎之官，负责升降冲和之气而运行不息。病位在胸中，上焦气机壅滞，必须因其病位在上而采用涌吐的方法，以此来祛除实邪并引导正气恢复。况且上脘部位的疾病，病位在上而未下行，务必迅速去除，如果不通过涌吐排出，邪气就会深入肠胃，传播到各条经络，还能治愈吗？所以，如果有宿食停滞且适合呕吐排出的，是指食物尚未进入肠胃的情况；有痰疟适合呕吐排出的，是指痰饮停蓄在胸膈的情况；有食毒或秽浊之气适合呕吐排出的，是担心邪气久留而加重；有肺痈或酒疸适合呕吐排出的，是因为患者胸满且心中烦闷。大抵上胸中邪气实盛，攻散不能解散，通达不能疏通，必须用酸苦性质的药物来催吐。因此，胃气不受损伤而病情容易痊愈。古人的大法则是：春季适宜用吐法，这是因为春气高而在上，上实下虚，治疗宜针对上部。又以寸口脉浮等脉象作为可吐的依据，是因为病位在膈膜之上，气机不能向下通畅，所以脉象浮。仔细审察这两点，那么吐法的应用，就不可以随意施用。
The *Huangdi Neijing* (Yellow Emperor's Inner Canon) states: "For those with pathogenic factors, soak the body to induce sweating." When the pathogen is in the skin and hair layer, disperse it by inducing sweat. It also says: "The body feels like burning charcoal; once sweat is released, the heat dissipates." Furthermore, it states: "If the illness has not yet passed three days, it can be cured by inducing sweat." Citing these four instances, generally speaking, when the pathogen is at the exterior, it must not be allowed to penetrate deeply; the key is to eliminate it through sweating.
However, sweating can become a habitual practice due to overuse, or it can lead to complications due to neglect of protection. There are cases where excessive sweating leads to unceasing leakage of sweat, which indicates deficiency of Yang Qi and weakness of the exterior. Conversely, insufficient sweating allows the pathogen to contend again with the healthy Qi. As ancient scholars discussed, incomplete sweating may cause the condition to transfer to the Yangming disease pattern. In such cases, Yin and Yang fail to achieve balance, and Ying (Nutritive) and Wei (Defensive) Qi fail to harmonize.
Nevertheless, diseases differ between interior and exterior patterns, and sweating is indicated only in specific cases. If sweating is forced when not indicated, it will consume Body Fluids. If sweating is required but not administered, the pathogen will deepen its position and transmit through the meridians, becoming as unstoppable as wind and rain. Records in various medical texts are numerous. Generally, conditions suitable for sweating present with fever and a floating pulse, such as Taiyang disease and Yangming disease. Conditions unsuitable for sweating include Shaoyang disease and Jueyin disease in terms of meridian involvement, Jue syndrome and Ni syndrome in terms of disease nature, as well as epistaxis, sores, and stranguria. Even if the pathogen is at the exterior, if the pulse is deep and slow, sweating will not resolve the condition. Moreover, although Taiyang disease is typically treated with sweating, some patients develop Jing (Spasm) syndrome after improper sweating. Although floating pulse and body pain usually indicate treatment via sweating, if the pulse at the Cun position on the radial artery (Chicun) is slow, sweating is contraindicated. This is another point that must be known.
The Sanjiao (Triple Burner) serves as the official responsible for dredging water passages, regulating the ascending and descending of Chong Qi (Pulsating Qi) without cease. When the disease is located in the chest, causing Qi stagnation in the Upper Jiao, one must employ the method of vomiting (inducing emesis) because the pathogen is high up. This eliminates excess pathogens and guides the recovery of healthy Qi. Furthermore, for diseases in the Shangwan (Upper Epigastrium), where the pathology is upper and has not descended, it is crucial to remove it quickly. If not expelled via vomiting, the pathogen will penetrate into the stomach and intestines and spread to various meridians, making it difficult to treat. Therefore, retained food that is suitable for vomiting refers to cases where the food has not yet entered the stomach and intestines. Phlegm-malaria suitable for vomiting refers to phlegm-fluid retention stored in the chest and diaphragm. Food toxicity or foul qi suitable for vomiting is addressed to prevent the pathogen from lingering and worsening. Lung abscess or jaundice caused by alcohol suitable for vomiting is indicated due to chest fullness and mental oppression. Generally, when excess pathogens accumulate in the chest and cannot be dispersed by attacking methods or unblocked by promoting methods, sour and bitter medicines must be used to induce vomiting. Thus, the Stomach Qi remains undamaged, and the disease heals easily. The ancient principle states that vomiting is appropriate in spring, as spring Qi rises upward, leading to excess above and deficiency below, necessitating treatment targeting the upper region. Additionally, a floating pulse at the Cunkou (Radial Artery) indicates suitability for vomiting, as the disease is located above the diaphragm, preventing Qi from descending smoothly, resulting in a floating pulse. By carefully examining these two aspects, the application of the vomiting method should never be applied recklessly.