陈无择云∶脾虚多病湿。内因酒面积多，过饮汤液，停滞腻物，烧炙膏粱过度，气
热熏蒸，浊液不行，涌溢于中，此湿从内作；外因坐卧湿地，雾露阴雨所客，澡浴为风
所关，涉水为湿所郁。郁于表腠则发黄。故经云∶地之湿气，感则害人皮肤筋脉。此湿
从外生，可见内外所感，皆由脾气虚弱，而湿邪乘而袭之。故曰∶壮者气行则愈，怯者着而
为病。
湿邪自外而感者，为表邪郁热，故发寒热，身如熏黄，皮肤着痹。清湿袭虚，而上为
头痛，鼻塞而烦；入骨节为重痛，足趺浮肿；脉浮缓。湿邪由内作者，为里结滞，故霍乱
吐利。重则发痉强直，轻则痞膈中满，怠惰嗜卧，沉重无力。流滥关节则烦痛，注于经络，
屈伸不得，气不能统则发肿，肉如泥，按之不起，其脉多沉。
经曰∶因于湿，首如裹，声如从室中言。湿热不已，熏蒸于上，则头重，目黄而鼻
塞也。故东垣云∶湿淫所胜，助风以平之，为湿邪之袭于上者也。
经曰∶伤于湿者，下先受之。故足 肿而膝重，无力以行。腿脚麻痹，腰腿为之不
利也。又曰∶腰重如带五千钱，皆湿邪之着于下者也。
《脉经》曰∶沉而缓、沉而细、微缓者，皆中湿。脉浮为风湿。浮而缓，湿在表也；
沉而缓，湿在里也。脉
沉细迟微为寒湿，为湿痹，脉滑疾，身热，烦喘，胸满口燥，发黄者，为湿热；洪而缓
者，皆湿热自甚而痛也。
陈无择说：脾气虚弱容易患湿病。内因方面，饮酒过量、饮食积滞，过多饮用汤水液体，食用油腻难消化之物，过度进食烧烤炙烤及肥甘厚味之品，导致热气熏蒸，体内浊液运行不畅，涌溢于中焦，这是湿气从内部产生；外因方面，久坐或卧于潮湿之地，受雾露阴雨侵袭，洗澡沐浴时被风邪所伤，涉水行走被湿邪郁阻。湿气郁结在体表腠理则会导致发黄。所以医经中说：大地的湿气，侵入人体就会伤害皮肤和筋脉。这是湿气从外部生成，可见无论是内感还是外受，都是因为脾气虚弱，使得湿邪趁机侵袭。所以说：身体强壮的人，气机通畅就能痊愈；体质虚弱的人，湿邪停留就会发病。
湿气从外部感受的，属于表邪郁热，所以会出现恶寒发热，身体像被烟熏一样发黄，皮肤出现着痹（感觉迟钝、麻木的痹证）。清冷潮湿之气侵袭虚处，向上则导致头痛、鼻塞且心烦；深入骨节则引起沉重疼痛，足背浮肿；脉象浮缓。湿气从内部产生的，属于里气结滞，所以会出现霍乱、呕吐腹泻。严重的会引发痉挛强直，轻微的会出现痞满膈塞、心中胀满、倦怠嗜睡、身体沉重无力。流注于关节则引起烦痛，注入经络则导致屈伸不利，气机不能统摄则发生水肿，肌肉松软如泥，按压后凹陷不起，其脉象多沉。
医经说：因为受湿邪困扰，头部感觉像被包裹一样沉重，说话声音好像从密闭房间中传出。如果湿热久治不愈，熏蒸于上部，就会导致头重、目黄和鼻塞。所以李东垣说：湿邪过盛，需用平肝熄风之法来治疗，这是针对湿邪侵袭上部的情况。
医经说：受伤于湿邪，下部先受到侵害。所以足部肿胀而膝盖沉重，无力行走。腿脚麻痹，腰腿部活动不便。又说：腰部沉重得像系着五千枚铜钱，这都是湿邪滞留于下部的表现。
《脉经》说：脉象沉而缓、沉而细、微缓的，都是中湿的表现。脉浮表示风湿。脉浮而缓，说明湿邪在表；脉沉而缓，说明湿邪在里。脉象沉细迟微，属于寒湿，属于湿痹；脉象滑疾，伴有身热、烦躁气喘、胸满口燥、发黄等症状，属于湿热；脉象洪大而缓，都是湿热严重而导致疼痛的情况。
Chen Wuyue stated: Spleen deficiency often leads to dampness-related diseases. Internally, excessive consumption of alcohol and food accumulation, drinking too much liquid, ingesting greasy and indigestible foods, and overeating roasted, grilled, or rich fatty foods cause heat to steam upward. This obstructs the flow of turbid fluids, causing them to surge within the middle jiao; this is dampness arising from within. Externally, sitting or lying on wet ground, being exposed to fog, dew, rain, and clouds, getting caught in the wind during bathing, or wading through water where dampness stagnates can lead to issues. If dampness stagnates in the exterior cou li (interstitial spaces), it causes jaundice. Thus, the Classics state: "The dampness of the earth, when it invades, harms the skin and sinews." This is dampness generated from the outside. It can be seen that both internal and external infections occur due to spleen qi deficiency, allowing pathogenic dampness to take advantage and invade. Therefore, it is said: "Those who are robust recover as their qi flows freely; those who are weak develop disease as the pathogen lingers."
When pathogenic dampness is contracted from the exterior, it constitutes an exterior pathogen with stagnant heat, thus causing aversion to cold and fever, a body color resembling smoke-staining (jaundice), and bi syndrome characterized by numbness and heaviness in the skin (Zhuo Bi). When clear cold-dampness attacks deficiency and moves upward, it causes headache, nasal congestion, and irritability; if it enters the bone joints, it causes heavy pain, edema of the dorsum of the foot, and a floating and moderate pulse. When dampness arises from within, it results in interior knotting and stagnation, leading to cholera-like vomiting and diarrhea. Severe cases may develop spasms and rigidity; mild cases present with epigastric fullness, diaphragmatic obstruction, abdominal distension, lethargy, drowsiness, heaviness, and weakness. If it floods the joints, it causes painful irritation; if it pours into the meridians, it limits flexion and extension. If qi fails to control fluid metabolism, edema occurs, with muscles soft like mud that do not rebound upon pressure, and the pulse is mostly deep.
The Classics state: "Affected by dampness, the head feels wrapped, and the voice sounds as if coming from inside a room." If damp-heat persists and steams upward, it causes heavy head, yellow eyes, and nasal congestion. Therefore, Li Dongyuan stated: "When dampness prevails excessively, use methods to calm wind to level it," referring to the treatment for dampness invading the upper body.
The Classics state: "Those injured by dampness suffer first in the lower part." Thus, the feet swell and the knees feel heavy, making walking difficult. Numbness in the legs and feet occurs, and the waist and legs become dysfunctional. It is also said: "A heavy sensation in the waist, as if carrying five thousand coins," all indicating dampness lodging in the lower body.
The Mai Jing (Pulse Classic) states: A pulse that is deep and moderate, deep and fine, or slightly moderate indicates dampness invasion. A floating pulse indicates wind-dampness. A floating and moderate pulse indicates dampness in the exterior; a deep and moderate pulse indicates dampness in the interior. A deep, fine, slow, and faint pulse indicates cold-dampness and damp-bi. A slippery and rapid pulse accompanied by fever, irritability, panting, chest fullness, dry mouth, and jaundice indicates damp-heat. A surging and moderate pulse indicates severe damp-heat causing pain.