经曰∶诸湿肿满，皆属于脾。又曰∶风雨则伤上，清湿则伤下。是湿之为病，有出于天气者，雨露是也；有
出地气者，泥水是也；有出饮食者，酒浆生冷是也；有出人事者，汗衣卧湿，如小儿澡浴，粪秽，衣褓不干，
皆是也。然所因虽异，悉由乎脾气之虚，而辨治之法，其要惟二∶一曰湿热，一曰寒湿尽之矣。病而发热者，谓
之湿热；病而多寒者，谓之寒湿。湿热之治，宜清宜利，热去湿亦去也；寒湿之治，宜燥宜温，非温不能燥也。
一湿热证∶其证发热身痛，多烦渴，小便赤涩，大便秘结，脉见洪滑，方是热证。宜利宜清，柴苓汤、茵
陈饮。如果湿热之甚，或元气壮而兼秘结不通者，方可推荡之，集成沆瀣丹。
一寒湿证∶惟胀满泄泻呕吐，皆寒湿之病也。凡小儿喜弄冷水，坐卧湿地。其证头痛身重，寒热往来，宜胃
苓汤。如兼呕吐，加藿香、砂仁。如因中湿浮肿者，胃苓汤合五
皮汤。如不效，必用温补，俟阳气渐复，则阴邪始退，如理中汤、八味丸，宜择用之。
凡脾虚多病湿，内因酒面停滞，嗜瓜果，喜生冷、烧炙甘肥，以致湿热壅溢而为病者，此内因也；复有坐
卧湿地，雾露阴雨所客，澡浴为风所闭，涉水为湿所郁，郁于肌腠则发黄，此湿由外生。可见内外所感，皆由
脾气虚弱，而湿邪乘而袭之。中湿发黄者，茵陈五苓散；不效，六君子汤燥里而黄自退。
《黄帝内经》说：各种湿邪导致的肿胀和腹满，都归属于脾。又说：风雨之邪容易伤害人体上部，清冷潮湿之邪容易伤害人体下部。因此，湿邪致病，有的源于天气，如雨露；有的源于地气，如泥水；有的源于饮食，如酒浆、生冷食物；有的源于人事，如穿着汗湿的衣服睡觉、处于潮湿环境，例如小儿洗澡后护理不当、接触粪便污秽、尿布或襁褓未干等，都是如此。然而，虽然致病原因各异，但根本原因在于脾气虚弱，而辨证治疗的要点只有两个方面：一是湿热，二是寒湿。患病时发热的，称为湿热证；患病时怕冷明显的，称为寒湿证。湿热证的治疗，宜用清热利湿的方法，热邪去除则湿邪也随之而去；寒湿证的治疗，宜用燥湿温中的方法，不用温法就不能燥湿。
第一种是湿热证：症状表现为发热、身体疼痛、心烦口渴、小便短赤涩痛、大便秘结，脉象洪大滑数，这才是热证。治疗宜通利、宜清热，可用柴苓汤（小柴胡汤合五苓散）、茵陈饮。如果湿热特别严重，或者患者元气壮实且兼有大便秘结不通的情况，才可以采用攻下推荡的方法，使用集成沆瀣丹。
第二种是寒湿证：主要表现为腹胀满、泄泻、呕吐，这些都是寒湿的病证。凡是小儿喜欢玩弄冷水，坐卧在潮湿之地，出现头痛、身体沉重、寒热往来的症状，宜用胃苓汤。如果兼有呕吐，加入藿香、砂仁。如果是因中湿导致浮肿的，用胃苓汤合五皮汤。如果无效，必须使用温补之法，等待阳气逐渐恢复，阴寒邪气才能消退，如理中汤、八味丸，可根据情况选择使用。
凡是脾气虚弱的人多患湿病，内因为饮酒、面食停滞，嗜好瓜果，喜食生冷、烧烤及甘甜肥腻食物，导致湿热壅滞溢满而发病的，这是内因；又有因坐卧湿地，受雾露阴雨侵袭，洗澡时被风邪闭塞毛孔，涉水时湿气郁阻，湿气郁积在肌肤腠理之间导致发黄，这是湿邪由外而生。由此可见，无论是内感还是外感，都是因为脾气虚弱，湿邪趁机侵袭所致。对于中湿发黄者，用茵陈五苓散；如果无效，用六君子汤燥湿健脾，黄疸自然消退。
The *Yellow Emperor's Inner Classic* states: "All dampness-induced swelling and fullness belong to the Spleen." It also says: "Wind and rain injure the upper part of the body, while cold-dampness injures the lower part." Therefore, diseases caused by dampness may originate from heavenly qi (such as rain and dew), earthly qi (such as mud and water), diet (such as alcoholic beverages, raw and cold foods), or human activities (such as sleeping in sweat-soaked clothes, lying in damp environments, such as improper care after a child's bath, contact with fecal matter, or wet diapers/swaddling clothes). Although the causes differ, they all stem from deficiency of Spleen Qi. The key to differentiation and treatment lies in two aspects: one is Damp-Heat, and the other is Cold-Damp. When the disease presents with fever, it is called Damp-Heat; when it presents with pronounced cold sensations, it is called Cold-Damp. The treatment for Damp-Heat should focus on clearing heat and promoting diuresis; once the heat is eliminated, the dampness will also dissipate. The treatment for Cold-Damp should focus on drying dampness and warming the middle; without warmth, dampness cannot be dried.
First, Damp-Heat Syndrome: Symptoms include fever, body pain, irritability, thirst, dark and scanty urine, constipation, and a surging and slippery pulse. This indicates a heat pattern. Treatment should involve promoting urination and clearing heat, using formulas such as Chai Ling Tang (Bupleurum and Five-Ingredient Poria Decoction) or Yin Chen Yin (Artemisia Capillaris Drink). If the damp-heat is severe, or if the patient has robust Yuan Qi accompanied by obstinate constipation, purgative methods may be employed, such as Jicheng Hangxie Dan (Jicheng Hengxiao Pill).
Second, Cold-Damp Syndrome: Manifestations are primarily abdominal distension, diarrhea, and vomiting, which are diseases of cold-dampness. Whenever children play with cold water or sit/lie on damp ground, presenting with headache, heavy body, and alternating chills and fever, Wei Ling Tang (Atractylodes Macrocephala and Five-Ingredient Poria Decoction) is appropriate. If vomiting is present, add Huoxiang (Patchouli Herb) and Sharen (Amomum Fruit). If edema results from dampness invasion, combine Wei Ling Tang with Wupi Tang (Five-Peel Decoction). If there is no improvement, warming and tonifying methods must be used; waiting for Yang Qi to gradually recover allows Yin pathogenic factors to recede. Formulas such like Lizhong Tang (Regulate the Middle Decoction) or Bawei Wan (Eight-Ingredient Pill) should be selected according to the situation.
Generally, those with Spleen Qi deficiency are prone to dampness diseases. Internal causes include stagnation from alcohol and wheat products, preference for melons and fruits, and liking for raw/cold foods, roasted items, and sweet/fatty foods, leading to accumulation and overflow of damp-heat. These are internal causes. External causes include sitting/lying on damp ground, exposure to fog/dew/rain, pore closure due to wind during bathing, or dampness retention from wading through water. When dampness stagnates in the muscle-couplings, jaundice may develop; this is dampness generated externally. Thus, whether internally or externally contracted, the root cause is weak Spleen Qi, allowing dampness pathogens to invade. For jaundice caused by dampness invasion, Yinchen Wuling San (Artemisia Capillaris and Five-Ingredient Poria Powder) is indicated. If ineffective, Liujunzi Tang (Six-Gentlemen Decoction) is used to dry dampness and strengthen the interior, causing the jaundice to subside naturally.