丹溪云∶夫湿者土之气，土者火之子，故湿病多自热生，盖火热能生土湿也。或曰∶湿
温风湿寒湿矣，未闻有所谓湿热病者。由六气之中，湿热为病，十居八九，故《内经》云∶
湿上润而热。又云∶因于湿，首如裹，湿热不攘，大筋软短，小筋驰长，软短为拘，弛长为
痿。或云∶温热在其中。又云∶湿热在其中。此古人论其细微之处。世之有病湿者，或处卑
湿，或冒雨露，或卧阴润，或衣湿汗，俱能致害。其病关节疼痛而烦，肢体顽麻而重，脉沉
细者名曰湿痹，其小便不利，大便反快者，当利其小便，或身痛而烦，脉沉而缓，名曰重湿
。患一身尽痛发黄，小便自利，当燥阴土。若肢体重着者可转侧，额上微汗，不欲去被，身
微肿，或脉浮者，名曰风湿，是真风湿二气相搏以致此，治当微微发汗，使风湿俱从汗出。
若大发汗，则风去而湿存，两胫逆冷，胸腹满，头自痛，多汗妄言，脉阳濡溺，阴急小，是
名湿温。因伤湿而复伤暑者，湿热相搏而成此患，不可发汗，汗则必不能言及耳聋，不知痛
痒，乃是重 。湿家寒多者，为痛为肿。凡湿家不可大下，下之额上汗出，微喘，小便利者
不治，下利不止者亦不治。又有脾胃素弱，内蓄痰饮，外冒雨露，痰湿相搏，上冲心胸令人
涎潮壅塞，口眼歪斜，半身不随，昏不知人，与中风相似，但脉沉涩或沉而细，不可作中风
治之，谓其脾土好干恶湿，而被湿流相干，则有是疾，若作中风治之，脾元愈虚，痰湿愈盛
，必致危笃。戴人论湿之证，而以湿热为源，风寒为兼，深得《内经》之旨也。治湿得行则
涣然，而湿行而气复散，临时开也。殊不知湿得行，则豁然而收也，湿得卫也，或从针灸而
得安，有以其开通而壅滞，殊不知湿得开通而壅滞行，如此亦用权者有可劫之病也，要当分
别上下内外之由，自外而感者，或因雾露阴雨所客，澡浴为风所关，涉水为寒所郁，汗出当
风而快坐卧，卑地清气袭虚，从下而起，上为头重，鼻塞而烦，表郁则发寒热，身色如似熏
黄，着入骨节，为重疼痛，足趺浮肿，其脉浮缓。《内经》曰∶地之湿气，感则害人皮肉筋
脉。又云∶伤于湿者下先受之，非外感所致乎。大法腰以上宜汗，腰以下宜利小便之分。东
垣云∶湿淫所胜，助风以平之，非风药表散之谓乎？经云∶湿上甚而热，治以苦温，佐以甘
辛，以汗为故而止。此治上治外之法也。自内而致者，或因酒面积多，过饮汤液停滞腻物，
甘滑陈久，烧炙香辛，膏粱过度，气热熏蒸，浊液不行，涌溢于中，湿从内作，重则发痉强
直，霍乱吐利，轻则痞膈中满，怠惰嗜卧，沉重无力，流滥关节则烦疼，注于络脉，屈伸不
可转侧。水性润下，气不能煦，滞于经络，发肿肉软如泥，按之不起，其脉多沉潜。《内经
》曰∶湿气在中。又曰∶脾恶湿，非内致所生乎，治法脾苦湿，急食苦以燥之。又曰∶湿淫
于内，以苦燥之，以淡泄之。此湿自内成，故宜燥宜利小便，非表散所能去也，此内治下之
法也。今湿分上下内外，盖可知矣，药亦有所据乎？《金匮》方以汗药发湿者也，古方以热
药燥寒湿者也，东垣以风药胜湿者也，河间以凉药治湿热者也。大率言淡渗之药，利湿者也
，诸家发明，互相迨矣。前人所述一证，各有立论，全在医者识病，或内因外因，或虚或实
，六淫七情所感，的于何经受证以致之，治之无不效矣。
朱丹溪说：湿是土的气化表现，土是火所生之子（五行中火生土），所以湿病多由热产生，因为火热之气能滋生土的湿气。有人问：虽然有温、风、寒、湿等论述，却没听说过有“湿热病”这一说法。其实，在六气致病中，湿热为患占了十之八九，所以《内经》说：“湿性上润而伴热。”又说：“因于湿邪，头部感觉像被包裹一样沉重；若湿热不除，大筋会收缩变短，小筋会松弛变长；收缩变短导致拘挛，松弛变长导致痿软无力。”有人说：“温热在其中。”又说：“湿热在其中。”这是古人对病情细微之处的论述。世间患有湿病的人，有的居住在低洼潮湿之地，有的冒雨淋露，有的睡在阴冷湿润处，有的穿着汗湿的衣服，这些都能导致疾病。其症状表现为关节疼痛且烦躁，肢体麻木沉重，脉象沉细的，名叫湿痹；如果小便不通利，大便反而稀溏的，应当通利小便；如果身体疼痛且烦躁，脉象沉而缓的，名叫重湿。如果全身疼痛且发黄，小便自利通畅的，应当燥化脾土（阴土）。如果肢体沉重但尚可转侧，额头微汗，不想盖被子，身体轻微浮肿，或者脉象浮的，名叫风湿，这是真风湿二气相搏结导致的，治疗应当微微发汗，使风湿之邪一同从汗液排出。如果大发汗，则风邪去而湿邪存留，会出现两小腿逆冷，胸腹胀满，头痛，多汗胡言乱语，脉象阳部濡软、阴部急小，这名叫湿温。如果因伤湿又复感暑邪，湿热相搏结而成此病，不可发汗，若发汗则必然导致不能言语及耳聋，不知痛痒，这叫做重暍（中暑重症）。湿病患者若寒邪偏多，则表现为疼痛和肿胀。凡是湿病患者不可用峻下法，若误用峻下，出现额头出汗，微喘，小便通利的，属于不治之症；若腹泻不止的，也是不治之症。又有脾胃素来虚弱，体内蓄积痰饮，外部又冒受雨露，痰湿相互搏结，向上冲撞心胸，导致涎沫潮涌壅塞，口眼歪斜，半身不遂，昏迷不省人事，这与中风相似，但脉象沉涩或沉而细，不可当作中风治疗。这是因为脾土喜干恶湿，被湿邪流注干扰，才产生这种疾病，如果当作中风治疗，脾气元气更加虚弱，痰湿更加旺盛，必定导致病情危重。戴人（张从正）论述湿证，以湿热为源头，风寒为兼夹，深得《内经》的宗旨。治疗湿证，只要湿气得以运行，病势就会涣散解除；湿气运行而气机恢复散布，临时闭塞的情况就会打开。殊不知湿气得以运行，就会豁然开朗而痊愈；湿气得到卫气的固护，或者通过针灸治疗而安宁。有些医生认为开通会导致壅滞，殊不知湿气得到开通后，壅滞才会运行，这也是权变之法，对于可劫夺治疗的疾病有效，关键在于区分上下内外的病因。从外部感受的，可能是因为雾露阴雨侵袭，洗澡时受风关阻，涉水受寒气郁闭，出汗后当风而坐卧，低地清气侵袭虚处，病邪从下而起，上行导致头重，鼻塞且烦躁，表气郁闭则发寒热，面色黄如熏黄，深入骨节，成为沉重疼痛，足背浮肿，脉象浮缓。《内经》说：“地的湿气，侵入人体则伤害皮肉筋脉。”又说：“伤于湿邪，下部先受之”，这不是外感所致吗？大法则是腰部以上宜用发汗法，腰部以下宜用通利小便法。李东垣说：“湿淫胜复，助风药以平之”，难道不是指用风药解表发散吗？经书说：“湿邪在上且伴有热，用苦温药治疗，佐以甘辛药，以出汗为愈，汗出即止。”这是治疗上部、外部的方法。从内部产生的，可能是因为酒食过量，过饮汤液，停滞腻物，甘甜滑腻之物陈久变质，烧炙香辛，膏粱厚味过度，热气熏蒸，浊液不行，涌溢于中，湿气从内生发，重的则发生痉挛强直，霍乱吐泻，轻则痞闷膈塞，脘腹胀满，怠惰嗜睡，沉重无力，流注关节则烦疼，注入络脉，屈伸不能转侧。水性润下，阳气不能温煦，停滞于经络，发生肿胀，肌肉松软如泥，按之不起，脉象多沉潜。《内经》说：“湿气在中。”又说：“脾恶湿”，这不是内生的吗？治法是脾苦于湿，急需食用苦味药以燥湿。又说：“湿气淫溢于内，用苦味药燥湿，用淡味药泄湿。”这是湿气自内生成，所以适宜燥湿、利小便，不是解表发散所能去除的，这是内部治疗下部的方法。如今湿病分为上下内外，大概可以知道了，用药也有依据吗？《金匮要略》方剂是用发汗药来发散湿邪的，古方是用热药来燥化寒湿的，李东垣是用风药来胜湿的，刘河间是用凉药来治疗湿热的。大致来说，淡渗的药物，是用来利湿的，各家学说互相阐发，已很完备了。前人所述每一种证候，各有立论，全在于医生识别病症，无论是内因还是外因，是虚还是实，六淫七情所感，明确在哪一经受证而导致，治疗没有不有效的。
Zhu Danxi stated: Dampness is the qi manifestation of Earth. Since Earth is the child generated by Fire (in Five Elements theory, Fire generates Earth), dampness diseases often arise from Heat, as fiery heat can generate the dampness of Earth. Some ask: Although there are discussions on Warmth, Wind, Cold, and Dampness, no so-called "Damp-Heat disease" has been heard of. In fact, among the pathogenic factors of the Six Qi, Damp-Heat accounts for eight or nine out of ten cases. Therefore, *Nei Jing* (The Inner Canon) states: "Dampness tends to moisten upwards accompanied by Heat." It also says: "Due to Dampness, the head feels as if wrapped; if Damp-Heat is not eliminated, the large tendons become short and soft, while the small tendons become long and lax. Shortening leads to spasms/cramps, while laxity leads to flaccidity/paralysis." Some say: "Warmth is within it." Others say: "Damp-Heat is within it." These are the ancients' discussions on the subtle aspects of the condition. People in the world suffering from Dampness diseases may dwell in low, damp places, be exposed to rain and dew, lie in cold and moist environments, or wear sweat-drenched clothes, all of which can cause harm. Their symptoms include joint pain with irritability, limb numbness and heaviness, and a deep, fine pulse, named Shi Bi (Dampness Bi syndrome). If urination is difficult but stool is loose, one should promote diuresis. If body pain with irritability occurs with a deep and slow pulse, it is named Chong Shi (Heavy Dampness). If the whole body hurts and turns yellow with free urination, one should dry the Spleen Earth. If limbs are heavy but movable, with slight sweating on the forehead, aversion to removing blankets, slight edema, or a floating pulse, it is named Feng Shi (Wind-Dampness), caused by the struggle between true Wind and Dampness. Treatment should involve mild diaphoresis to expel both Wind and Dampness through sweat. Profuse sweating will expel Wind but retain Dampness, leading to cold legs, chest and abdominal fullness, headache, excessive sweating, delirium, and a pulse that is soggy at the Yang position and urgent/small at the Yin position, named Shi Wen (Damp-Warmth). If Dampness injury is compounded by Summerheat, forming this condition via Damp-Heat struggle, diaphoresis is contraindicated; inducing sweat will likely cause aphonia, deafness, and loss of pain/temperature sensation, known as Zhong Yue (Severe Summerheat). For patients with excess Cold-Dampness, pain and swelling occur. Purging is strictly forbidden in Dampness patients; if purging causes forehead sweating, slight wheezing, and free urination, it is incurable; likewise, unceasing diarrhea is incurable. Those with inherent weak Spleen and Stomach, retaining phlegm-fluids internally, and exposed to external dampness, may experience Phlegm-Dampness struggling and rushing upward to the chest and heart, causing salivary flooding and obstruction, facial paralysis, hemiplegia, and coma, resembling Stroke (Zhong Feng). However, the pulse is deep and choppy or deep and fine, so it must not be treated as Stroke. This is because the Spleen Earth prefers dryness and dislikes dampness; when invaded by flowing dampness, such diseases arise. Treating it as Stroke would further weaken Spleen Yuan Qi and increase Phlegm-Dampness, leading to critical danger. Dai Ren (Zhang Congzheng) discussed Dampness syndromes, identifying Damp-Heat as the source and Wind-Cold as concurrent factors, deeply grasping the essence of *Nei Jing*. Treating Dampness allows its movement, dispersing the pathogen; as Dampness moves, Qi circulation resumes, resolving temporary blockages. Unknowingly, once Dampness moves, recovery is sudden; with Wei Qi support, or via acupuncture, peace is restored. Some physicians believe opening up causes stagnation, unaware that opening facilitates Dampness movement; this is a flexible approach for treatable conditions, requiring differentiation of upper/lower and internal/external origins. External contraction may result from mist, rain, or clouds, wind exposure during bathing, cold depression from wading, or sitting/lying in drafts after sweating. Clear qi from low ground invades deficiency, rising from below to cause heavy head, nasal congestion, and irritability. Exterior constraint causes chills and fever, sallow complexion like smoked yellow, deep penetration into joints causing heavy pain, dorsal foot edema, and a floating-slow pulse. *Nei Jing* says: "Earth's dampness, when invading, harms skin, flesh, tendons, and vessels." It also says: "Those injured by Dampness are first affected below," indicating external contraction. The general rule is: above the waist, use diaphoresis; below the waist, use diuresis. Li Dongyuan said: "When Dampness prevails, assist with Wind herbs to pacify it," referring to using Wind herbs for exterior dispersion. Classics state: "For Dampness prevailing above with Heat, treat with Bitter-Warm herbs, assisted by Sweet-Acrid herbs, stopping when sweat occurs." This is the method for treating Upper and Exterior. Internal generation may result from excessive alcohol and food, overconsumption of liquids, stagnation of greasy foods, aged sweet/slippery items, roasted/spicy foods, or excessive rich diet. Qi-Heat steaming causes turbid fluids to stagnate and overflow internally, generating Dampness from within. Severe cases cause spasms and rigidity, cholera-like vomiting and diarrhea; mild cases cause epigastric fullness, lethargy, drowsiness, heaviness, and weakness. Flowing into joints causes painful irritation; entering collaterals prevents flexion and extension. Water nature is moist and downward; without Yang warmth, stagnation in collaterals causes edema and soft muscles like mud, leaving indentations upon pressure, with a deep-submerged pulse. *Nei Jing* says: "Dampness is within." It also says: "Spleen dislikes Dampness," indicating internal origin. Treatment: Spleen suffers from Dampness, urgently use Bitter herbs to dry it. Also: "When Dampness invades internally, use Bitter to dry, and Pale to drain." Since Dampness forms internally, drying and diuresis are appropriate, not exterior dispersion. This is the method for treating Internal and Lower. Thus, Dampness is divided into Upper/Lower and Internal/External, with corresponding herbal strategies. *Jin Gui Yao Lue* formulas use diaphoretics to disperse Dampness; ancient formulas use Hot herbs to dry Cold-Dampness; Li Dongyuan uses Wind herbs to overcome Dampness; Liu Hejian uses Cool herbs to treat Damp-Heat. Generally, Pale-draining herbs promote Dampness elimination. Various schools have elaborated mutually. Predecessors described each syndrome with specific theories; success depends on the physician's ability to identify the disease, whether internal/external, deficiency/excess, or influenced by Six Excesses or Seven Emotions, pinpointing the affected meridian for effective treatment.