论病之原，以内伤、外感，四字括之。论病之情，则以寒、热、虚、实、表、里、阴、
阳，八字统之。而论治病之方，则又以汗、和、下、消、吐、清、温、补，八法尽之。盖一
法之中，八法备焉。八法之中，百法备焉。病变虽多，而法归于一。此予数十年来，心领神
会，历试而不谬者，尽见于八篇中矣。学人诚熟读而精思之，于以救济苍生，亦未必无小补
汗者，散也。经云∶邪在皮毛者，汗而发之是也。又云∶体若燔炭，汗出而散是也。
然有当汗不汗误人者，有不当汗而汗误人者。有当汗不可汗，而妄汗之误人者。有当汗不可
汗，而又不可以不汗，汗之不得其道以误人者。有当汗而汗之不中其经，不辨其药，知发而
不知敛以误人者。是不可以不审也。
何则？风寒初客于人也，头痛发热而恶寒，鼻塞声重而体痛，此皮毛受病，法当汗之，
若失时不汗，或汗不如法，以致腠理闭塞，荣卫不通，病邪深入，流传经络者有之，此当汗
亦有头痛发热与伤寒同，而其人倦怠无力，鼻不塞，声不重，脉来虚弱，此内伤元气不
足之证；又有劳心好色，真阴亏损，内热、晡热，脉细数而无力者；又有伤食病，胸膈满闷
吞酸嗳腐，日晡潮热，气口脉紧者；又有寒痰厥逆，湿淫香港脚，内痈、外痈，瘀血凝积，
以及风温、湿温，中暑自汗诸症，皆有寒热，与外感风寒似同而实异，若误汗之，变症百出
矣。所谓不当汗而汗者此也。
若夫症在外感应汗之例，而其人脐之左右上下，或有动气，则不可以汗。经云∶动气在
右，不可发汗，汗则衄而渴、心烦、饮水即吐。动气在左，不可发汗，汗则头眩、汗不止、
筋惕肉 。动气在上，不可发汗，汗则气上冲，正在心中。动气在下，不可发汗，汗则
无汗，心大烦、骨节疼、目运、食入则吐、舌不得前。又脉沉咽燥，病已入里，汗之则津液
越出，大便难而谵语。又少阴证，但厥无汗，而强发之，则动血，未知从何道出，或从耳目
或从口鼻出者，此为下厥上竭，为难治。又少阴中寒，不可发汗，汗则厥逆蜷卧，不
能自温也。又寸脉弱者，不可发汗，汗则亡阳。尺脉弱者，不可发汗，汗则亡阴也。又诸亡
血家不可汗，汗则直视、额上陷。淋家不可汗，汗则便血。疮家不可汗，汗则痉。又伤寒病
在少阳，不可汗，汗则谵妄。又坏病、虚人，及女人经水适来者，皆不可汗，若妄汗之，变
症百出矣。所谓当汗不可汗，而妄汗误人者此也。
夫病不可汗，而又不可以不汗，则将听之乎？是有道焉，伤寒赋云∶动气理中去白术，
是即于理中汤去术而加汗药，保元气而除病气也。又热邪入里而表未解者，仲景有麻黄石膏
之例，有葛根黄连黄芩之例，是清凉解表法也。又太阳证、脉沉细，少阴证、反发热者，有
麻黄附子细辛之例，是温中解表法也。又少阳中风，用柴胡汤加桂枝，是和解中兼表法也。
又阳虚者，东垣用补中汤加表药。阴虚者，丹溪用芎归汤加表药，其法精且密矣。总而言之
凡一切阳虚者，皆宜补中发汗。一切阴虚者，皆宜养阴发汗。挟热者，皆宜清凉发汗。挟
寒者，皆宜温经发汗。伤食者，则宜消导发汗。感重而体实者，汗之宜重，麻黄汤。感轻而
体虚者，汗之宜轻，香苏散。又东南之地，不比西北，隆冬开花，少霜雪，人禀常弱，腠理
空疏，凡用汗药，只须对症，不必过重。予尝治伤寒初起，专用香苏散加荆、防、川芎、秦
艽、蔓荆等药，一剂愈，甚则两服，无有不安。而麻黄峻剂，数十年来，不上两余。可见地
土不同，用药迥别。其有阴虚、阳虚、挟寒、挟热、兼食而为病者，即按前法治之，但师古
人用药之意，而未尝尽泥其方，随时随证酌量处治，往往有验。此皆已试之成法，而与斯世
共白之。所以拯灾救患者，莫切乎此。此汗之之道也。
且三阳之病，浅深不同，治有次第。假如症在太阳，而发散阳明，已隔一层。病在太阳
阳明，而和解少阳，则引贼入门矣。假如病在二经，而专治一经，已遗一经。病在三经，而
偏治一经，即遗二经矣。假如病在一经，而兼治二经，或兼治三经，则邪过经矣。况太阳无
汗，麻黄为最。太阳有汗，桂枝可先。葛根专主阳明，柴胡专主少阳。皆的当不易之药。
至于九味羌活，乃两感热证三阳三阴并治之法，初非为太阳一经设也。又柴葛解肌汤，乃治
春温夏热之证，自里达表，其症不恶寒而口渴。若新感风寒，恶寒而口不渴者，非所宜也。又
伤风自汗，用桂枝汤，伤暑自汗，则不可用，若误用之，热邪愈盛而病必增剧。若于暑症而
妄行发散，复伤津液，名曰重 ，多致不救。古人设为白术、防风例以治风，设益元散
、香薷饮以治暑，俾不犯三阳禁忌者，良有以也。
又人知发汗退热之法，而不知敛汗退热之法。汗不出则散之，汗出多则敛之。敛也者
非五味、酸枣之谓，其谓致病有因，出汗有由，治得其宜，汗自敛耳。譬如风伤卫汗自出
者，以桂枝汤和荣卫，祛风邪而汗自止。若热邪传里，令人汗出者，乃热气熏蒸，如釜中吹
煮，水气旁流，非虚也，急用白虎汤清之。若邪已结聚，不大便者，则用承气汤下之，热气
退而汗自收矣。此与伤暑自汗略同。但暑伤气，为虚邪，只有清补并行之一法。寒伤形，为
实邪，则清热之外，更有攻下止汗之法也。复有发散太过，遂至汗多亡阳，身 动欲擗
地者，宜用真武汤。此救逆之良药，与中寒冷汗自出者，同类并称。又与热证汗出者，大相
径庭矣。其他少阳证，头微汗，或盗汗者，小柴胡汤。水气症，头汗出者，小半夏加茯苓汤
至于虚人自汗、盗汗等症，则归脾、补中、八珍、十全，按法而用，委曲寻绎，各尽其妙
而后即安，所谓汗之必中其经，必得其药，知发而知敛者此也。嗟嗟！百病起于风寒，风
寒必先客表，汗得其法，何病不除！汗法一差，夭枉随之矣。吁！汗岂易言哉！
论述疾病的根源，可以用“内伤”和“外感”四个字来概括。论述病情的性质，可以用“寒、热、虚、实、表、里、阴、阳”八个字来统摄。而论述治疗疾病的方法，则用“汗、和、下、消、吐、清、温、补”八法来穷尽。可以说，在一法之中，包含了八法的完备；在八法之中，包含了百法的完备。病变虽然繁多，但法则归于统一。这是我几十年来心领神会、反复验证而不出差错的经验，全部体现在这八篇论述中了。学习者如果确实能熟读并深入思考它，以此来救济百姓，也未必没有微小的帮助。
所谓“汗”，就是发散的意思。医经说：“邪气在皮毛的，应当用发汗的方法来驱散。”又说：“身体像燃烧的炭火一样烫，出汗后热势就会消散。”然而，有应当发汗却没有发汗而误人的，有不应当发汗却发汗而误人的。有应当发汗但实际上不可发汗，却妄自发汗而误人的。有应当发汗但实际上不可发汗，却又不能不发汗，发汗不得其道而误人的。有应当发汗但发汗没有中其经络，不辨别药物，只知道发散却不知道收敛而误人的。这些情况是不可以不审慎考察的。
为什么呢？风寒初侵人体时，出现头痛、发热、恶寒，鼻塞、声音重浊且身体疼痛，这是皮毛受病，依法应当发汗。如果错过时机不发汗，或者发汗不符合法度，导致腠理闭塞，营卫不通，病邪深入，流传于经络的情况是有的。这种情况下，虽然也有头痛、发热与伤寒相同，但患者倦怠无力，鼻子不塞，声音不重，脉象虚弱，这是内伤元气不足的证候；又有因劳心过度、房事不节，导致真阴亏损，出现内热、傍晚发热（晡热），脉细数而无力的；又有伤食病，胸膈满闷、吞酸、嗳气腐臭，傍晚潮热，气口脉紧的；又有寒痰厥逆、湿邪引起的脚气（香港脚）、体内痈肿、体表痈肿、瘀血凝积，以及风温、湿温、中暑自汗等各种病症，都有寒热表现，与外感风寒看似相同实则不同，如果误用发汗法，变症就会层出不穷。这就是所谓的“不当汗而汗”。
至于症状属于外感应发汗的例子，但如果患者脐部左右上下有动气，则不可以发汗。医经说：“动气在右，不可发汗，发汗则会导致鼻出血、口渴、心烦、喝水即吐。”动气在左，不可发汗，发汗则会导致头晕、汗出不止、筋肉跳动。动气在上，不可发汗，发汗则会导致气上冲，直冲心胸。动气在下，不可发汗，发汗则会导致无汗、心中大烦、骨节疼痛、眼花、进食即吐、舌头僵硬不能前伸。还有脉沉咽燥，病已入里，发汗则津液外越，导致大便困难和胡言乱语。还有少阴证，只有四肢厥冷而无汗，如果强行发汗，则会扰动血液，不知道从哪个部位出血，有的从耳目出，有的从口鼻出，这叫作“下厥上竭”，属于难治之症。还有少阴中寒，不可发汗，发汗则会导致四肢厥冷、蜷卧，无法自我温暖。还有寸脉弱的，不可发汗，发汗则会导致亡阳。尺脉弱的，不可发汗，发汗则会导致亡阴。还有各种失血患者不可发汗，发汗则会导致两眼直视、额动脉陷。淋病患者不可发汗，发汗则会导致便血。疮疡患者不可发汗，发汗则会导致痉病。还有伤寒病在少阳，不可发汗，发汗则会导致胡言乱语。还有坏病、体虚之人，以及妇女月经适至者，都不可发汗，如果妄自发汗，变症就会层出不穷。这就是所谓的“当汗不可汗，而妄汗误人”。
既然病不可发汗，但又不能不发汗，那就要听之任之吗？是有方法的。《伤寒赋》说：“有动气的，用理中汤去白术”，这就是在理中汤中去掉白术而加入发汗药，以保护元气而祛除病邪。还有热邪入里而表证未解的，张仲景有麻黄石膏的用法，有葛根黄连黄芩的用法，这是清凉解表法。还有太阳证脉沉细，少阴证反而发热的，有麻黄附子细辛的用法，这是温中解表法。还有少阳中风，用柴胡汤加桂枝，这是和解中兼有解表的方法。还有阳虚的人，李东垣用补中益气汤加解表药。阴虚的人，朱丹溪用芎归汤加解表药，这些方法精妙严密。总而言之，凡是阳虚的，都适宜用补中发汗法。凡是阴虚的，都适宜用养阴发汗法。挟热的，都适宜用清凉发汗法。挟寒的，都适宜用温经发汗法。伤食的，则适宜用消导发汗法。感受邪气重而体质实的，发汗宜重，用麻黄汤。感受邪气轻而体质虚的，发汗宜轻，用香苏散。另外，东南地区，不同于西北地区，隆冬时节开花，少霜雪，人的禀赋通常较弱，腠理空疏，凡是用发汗药，只要对症即可，不必过重。我曾经治疗伤寒初起，专门用香苏散加荆芥、防风、川芎、秦艽、蔓荆子等药，一剂痊愈，严重的服两剂，没有不安稳的。而麻黄这种峻猛的药剂，几十年来，我不过用了两次而已。可见地域不同，用药截然不同。那些有阴虚、阳虚、挟寒、挟热、兼食积而致病的人，就按照前面的方法治疗，只是效法古人用药的心意，而不曾完全拘泥于古方，随时根据病情斟酌处置，往往有效。这些都是已经验证过的成法，现在公之于世。所以拯救灾难、救治患者的，没有比这更迫切的了。这就是汗法的道理。
况且三阳经的病，深浅不同，治疗要有次第。假如病在太阳经，却发散阳明经的药，那就隔了一层。病在太阳、阳明经，却用和解少阳经的方法，那就是引贼入门了。假如病在两条经脉，却只治一条经脉，那就遗漏了一条经脉。病在三条经脉，却偏治一条经脉，那就遗漏了两条经脉了。假如病在一条经脉，却兼治两条经脉，或兼治三条经脉，那么邪气就会传过经脉了。何况太阳经无汗，麻黄最为合适。太阳经有汗，桂枝可以先用。葛根专主阳明经，柴胡专主少阳经。都是确切恰当、不可更改的药物。至于九味羌活汤，乃是两感热证、三阳三阴并治的方法，原本就不是为太阳一经设立的。还有柴葛解肌汤，是治疗春温夏热证的，由里达表，其症状是不恶寒而口渴。如果是新感风寒，恶寒而口不渴的，就不适宜用。还有伤风自汗，用桂枝汤；伤暑自汗，则不可用，如果误用，热邪会更盛而病情必然加重。如果在暑症上妄行发散，再次损伤津液，名叫“重暍”，多导致死亡。古人设立白术、防风的例子来治风，设立益元散、香薷饮来治暑，使不触犯三阳禁忌的原因，确实是很有道理的。
又有人知道发汗退热的方法，却不知道敛汗退热的方法。汗不出则发散它，汗出多则收敛它。所谓“敛”，并不是指五味子、酸枣仁这类药，而是指致病有原因，出汗有缘由，治疗得当，汗自然就会收敛。比如风邪伤卫分导致自汗的，用桂枝汤调和营卫，祛除外风邪气而汗自然停止。如果热邪传入里，导致人出汗的，那是热气熏蒸，就像锅下面吹火煮水，水气从旁边流出，这不是虚证，急用白虎汤清热。如果邪气已经结聚，不大便的，就用承气汤攻下，热气退了汗自然就收了。这与伤暑自汗大致相同。但暑邪伤气，属于虚邪，只有清补并行的一种方法。寒邪伤形，属于实邪，则在清热之外，还有攻下止汗的方法。又有发散太过，导致汗多亡阳，身体颤动想要扑倒在地上的人，适宜用真武汤。这是救逆的良药，与中寒冷汗自出的人，同类并称。又与热证汗出的人，大相径庭了。其他如少阳证，头微汗，或盗汗的，用小柴胡汤。水气症，头汗出的，用小半夏加茯苓汤。至于虚人自汗、盗汗等症状，则用归脾汤、补中益气汤、八珍汤、十全大补汤，按法使用，委婉寻绎，各尽其妙之后才能安宁，这就是所谓的“发汗必中其经络，必得其药物，知道发散也知道收敛”的道理。唉！百病起于风寒，风寒必先客居体表，汗法得当，什么病不能去除！汗法一旦出差错，夭折枉死随之而来啊。唉！汗法岂是容易谈论的吗！
The origin of diseases can be summarized in four characters: "internal injury" (Nei Shang) and "external contraction" (Wai Gan). The nature of diseases can be encompassed by eight characters: "cold" (Han), "heat" (Re), "deficiency" (Xu), "excess" (Shi), "exterior" (Biao), "interior" (Li), "yin" (Yin), and "yang" (Yang). Regarding the methods of treatment, they are fully covered by the Eight Methods: "diaphoresis" (Han), "harmonization" (He), "purging" (Xia), "elimination" (Xiao), "emesis" (Tu), "clearing" (Qing), "warming" (Wen), and "tonification" (Bu). Indeed, within one method, all eight methods are contained; within the eight methods, a hundred methods are contained. Although pathological changes are numerous, the principles converge into one. These are experiences I have deeply understood and verified without error over decades, fully presented in these eight chapters. If students study them diligently and reflect profoundly, they may offer some assistance in saving the people.
"Diaphoresis" refers to dispersion. The Classics state: "When pathogenic factors are in the skin and hair, disperse them through sweating." It also states: "If the body is hot as burning charcoal, it will cool down after sweating." However, errors occur when diaphoresis is indicated but not performed, when it is not indicated but performed, when it is indicated yet contraindicated but wrongly applied, when it is indicated yet contraindicated but necessary, and when the method is incorrect. There are cases where diaphoresis does not target the correct meridian, drugs are not distinguished, and only dispersion is known without restraint, leading to harm. These situations require careful scrutiny.
Why? When wind-cold initially invades the human body, symptoms include headache, fever, aversion to cold, nasal congestion, heavy voice, and body pain. This indicates disease in the skin and hair, and diaphoresis is indicated. If missed or improperly performed, pores close, Ying and Wei Qi (Nutritive and Defensive Qi) become blocked, and pathogens deepen into meridians. In such cases, although headache and fever resemble Taiyang Cold Damage (Taiyang Shang Han), if the patient is fatigued, weak, with no nasal congestion, normal voice, and a weak pulse, it indicates internal injury with insufficient Yuan Qi (Original Qi). Other conditions include true yin deficiency from mental strain or sexual excess, presenting with internal heat, afternoon fever (Pu Re), and a fine, rapid, weak pulse; food stagnation causing chest fullness, acid regurgitation, belching of rotten smells, afternoon tidal fever, and a tight pulse at the Qi Kou position; cold phlegm with厥逆 (Jue Ni, reversal cold); dampness causing Hong Kong Jiao (Hong Xiang Jiao, gouty arthritis); internal and external abscesses; blood stasis; wind-warmth, damp-warmth, and summerheat with spontaneous sweating. All present with chills and fever resembling external wind-cold but are fundamentally different. Misapplying diaphoresis leads to myriad complications. This is "diaphoresis when not indicated."
For exterior patterns requiring diaphoresis, if there is "moving qi" (Dong Qi) around the navel, diaphoresis is contraindicated. The Classics state: "Moving qi on the right: do not sweat; sweating causes epistaxis, thirst, irritability, and vomiting upon drinking." "Moving qi on the left: do not sweat; sweating causes dizziness, continuous sweating, and muscle twitching." "Moving qi above: do not sweat; sweating causes qi rushing upward to the heart." "Moving qi below: do not sweat; sweating causes anhidrosis, severe cardiac irritability, bone joint pain, vertigo, vomiting upon eating, and tongue stiffness." Additionally, deep pulse with dry throat indicates interior disease; sweating depletes fluids, causing constipation and delirium. Shaoyin syndrome with cold limbs and no sweat should not be forcibly sweated, as this disturbs blood, potentially causing bleeding from ears, eyes, mouth, or nose, termed "lower jue and upper exhaustion," which is difficult to treat. Shaoyin cold damage cannot be sweated, as it worsens cold limbs and curling up. Weak cun pulse indicates yang deficiency; sweating causes yang collapse. Weak chi pulse indicates yin deficiency; sweating causes yin collapse. Patients with blood loss, chronic strangury, or sores must not be sweated, as it causes staring eyes, sunken forehead arteries, hematochezia, or spasms. Shaoyang syndrome cannot be sweated, causing delirium. Complicated cases, deficient patients, and women during menstruation must not be sweated, lest complications arise. This is "indicated for diaphoresis but contraindicated, wrongly applied."
If diaphoresis is contraindicated yet necessary, how to proceed? There are methods. The *Shang Han Fu* states: "For moving qi, use Lizhong Tang removing Atractylodes." This protects yuan qi while dispelling pathogens. For heat entering the interior with unresolved exterior, Zhang Zhongjing used Ma Huang Shi Gao (Ephedra and Gypsum Decoction) or Ge Gen Huang Lian Huang Qin (Kudzu, Coptis, and Scutellaria Decoction), representing cooling exterior resolution. For Taiyang pattern with deep/thin pulse and Shaoyin pattern with fever, Ma Huang Fu Zi Xi Xin (Ephedra, Prepared Aconite, and Asarum Decoction) warms the interior and resolves the exterior. For Shaoyang wind-stroke, Chai Hu Tang (Bupleurum Decoction) plus Gui Zhi (Cinnamon Twig) harmonizes and resolves the exterior. Li Dongyuan used Buzhong Yiqi Tang (Tonify the Middle and Augment the Qi Decoction) plus exterior-resolving herbs for yang deficiency; Zhu Danxi used Xiong Gui Tang (Szechwan Lovage and Angelica Decoction) plus exterior-resolving herbs for yin deficiency. These methods are precise. Generally, yang deficiency requires tonifying the middle to induce sweat; yin deficiency requires nourishing yin to induce sweat; heat requires cooling to induce sweat; cold requires warming meridians to induce sweat; food stagnation requires guiding digestion to induce sweat. Heavy exterior invasion with strong constitution warrants heavy diaphoresis (Ma Huang Tang); light invasion with weak constitution warrants light diaphoresis (Xiang Su San). Southeast regions differ from the Northwest; winter blooms, less frost/snow, weaker constitutions, and loose pores require mild diaphoresis. I treated early Shang Han with Xiang Su San plus Jing Jie, Fang Feng, Chuan Xiong, Qin Jiao, and Man Jing Zi, often curing in one dose. Ma Huang, a harsh agent, was rarely used. Regional differences dictate drug choices. For mixed patterns (yin/yang deficiency, cold/heat, food stagnation), apply previous methods flexibly, learning from ancient intent rather than rigidly following formulas. These proven methods are shared to save lives.
Diseases of the Three Yang meridians vary in depth and require sequential treatment. Treating Taiyang with Yangming-dispersing herbs misses the mark. Harmonizing Shaoyang for Taiyang/Yangming disease invites pathogens inward. Treating one meridian when two are affected leaves one untreated; treating one when three are affected leaves two untreated. Treating multiple meridians when only one is affected allows pathogens to spread. For Taiyang anhidrosis, Ma Huang is best; for Taiyang hyperhidrosis, Gui Zhi is first. Ge Gen targets Yangming; Chai Hu targets Shaoyang. These are reliable. Jiu Wei Qiang Huo Tang treats simultaneous cold-heat in Three Yin and Three Yang, not just Taiyang. Chai Ge Jie Ji Tang treats spring warmth/summer heat, resolving from interior to exterior, for non-chilly, thirsty patterns. It is unsuitable for new wind-cold with chills and no thirst. Gui Zhi Tang treats wind-cold with spontaneous sweating but is contraindicated for summerheat-induced sweating; misuse exacerbates heat. Sweating summerheat damages fluids, causing "Chong Ye" (Heavy Summerheat), often fatal. Ancient masters used Bai Zhu/Fang Feng for wind and Yi Yuan San/Xiang Ru Yin for summerheat to avoid Three Yang taboos.
People know diaphoresis reduces fever but not "restraining sweat" to reduce fever. No sweat requires dispersion; excessive sweat requires restraint. "Restraint" does not mean merely using sour astringents like Wu Wei Zi or Suan Zao Ren. It means addressing the cause of sweating appropriately so sweat stops naturally. Wind damaging Wei Qi causes spontaneous sweating; Gui Zhi Tang harmonizes Ying and Wei, dispels wind, and stops sweat. Heat entering the interior causes sweating via steaming, like boiling water; this is excess, not deficiency. Use Bai Hu Tang (White Tiger Decoction) to clear heat. If pathogens are bound with constipation, use Cheng Qi Tang (Order the Qi Decoction) to purge; heat subsides, sweat stops. Similar to summerheat sweating, but summerheat damages Qi (deficient evil), requiring clearing and tonifying. Cold damages Form (excess evil), allowing purging to stop sweat. Excessive diaphoresis causing yang collapse with tremors requires Zhen Wu Tang (True Warrior Decoction), a rescue remedy distinct from cold-damp sweating or heat-pattern sweating. Shaoyang patterns with slight head sweat or night sweats use Xiao Chai Hu Tang. Water retention with head sweat uses Xiao Ban Xia Jia Fu Ling Tang (Minor Pinellia Plus Poria Decoction). Deficient patients with spontaneous/night sweats use Gui Pi Tang, Buzhong Yiqi Tang, Ba Zhen Tang, or Shi Quan Da Bu Tang. Flexibility in application yields results. This is "targeting the correct meridian, using appropriate drugs, knowing both dispersion and restraint." Alas! Hundred diseases originate from wind-cold invading the exterior. Proper diaphoresis cures all; errors lead to premature death. How difficult is the Diaphoretic Method!