（寓木）渗脾肺湿伐肝胃水邪
茯苓（专入脾胃。兼入肺肝）。色白入肺。味甘入脾。味淡渗湿。故书皆载上渗脾肺之
湿。下
伐肝肾之邪。其气先升（清肺化源。）后降。（下降利水。）凡人病因水湿而见气逆烦满。心
下
结痛。呃逆呕吐。口苦舌干。水肿淋结。忧恚惊恐。及小便或涩或多者。（诸病皆从水湿所
生而言。）服此皆能有效。（故治亦从水湿生义。）故入四君。则佐参术以渗脾家之湿。入六
味。则使泽泻以行肾邪之余。最为利水除湿要药。书曰健脾。即水去而脾自健之谓也。又曰
定魄。（肺藏魄。）即水去而魄自安之意也。且水既去。则小便自开。安有癃闭之虑乎？水去
则内湿已消。安有小便多见之谓乎？故水去则胸膈自宽。而结痛烦满不作。水去则津液自生
。
而口苦舌干悉去。（故效亦从水湿既去而见。）惟水衰精滑。小便不禁。非由水湿致者切忌。
恐其走表泄气故耳。苓有赤白之分。赤入小肠。白入膀胱。白微有补。赤则止泻湿热。一气
一血。自不容混如此。至皮专治水肿肤胀。以皮行皮之义。（凡肿而烦渴。便闭溺赤。属阳
水。有五皮散疏凿饮。不烦渴。大便溏。小便数。不赤涩。属阴水。宜实脾饮疏气饮。腰以
上肿者宜汗。腰以下肿者宜利小便。）以大块坚白者良。（系松根灵气结成。）恶白蔹。畏地
榆秦艽龟甲雄黄。忌醋。
茯苓主要归入脾胃经，兼入肺经和肝经。其色白，故入肺经；味甘，故入脾经；味淡，具有渗湿作用。因此医书中都记载它能上渗脾肺之湿，下伐肝肾之邪。它的药气先升（清肃肺气以化生水源），后降（下降以利水）。凡是人体因水湿致病而出现的气逆、烦闷胀满、心下部结聚疼痛、呃逆呕吐、口苦舌干、水肿、淋证结滞、忧恚惊恐，以及小便或涩滞或频多等症状。（这些病症都是从水湿所生的角度而言的。）服用茯苓都能有效。（所以治疗也是基于去除水湿的原理。）
因此，茯苓加入四君子汤中，则辅助人参、白术来渗除脾脏的湿气；加入六味地黄丸中，则引导泽泻来行散肾脏的余邪。它是最为利水除湿的重要药物。书上说它能“健脾”，指的就是水湿去除了，脾脏自然强健的意思。又说它能“定魄”（肺藏魄），指的就是水湿去除了，魄自然安宁的意思。况且水湿既去，小便自然通畅，哪里还有癃闭（小便不通）的忧虑呢？水湿去除了，体内的湿气已经消除，哪里还会有小便过多的说法呢？所以水湿去除了，胸膈自然宽舒，结聚疼痛和烦闷胀满就不会发生；水湿去除了，津液自然生成，口苦舌干也就全部消除。（所以疗效也是在水湿既去之后才显现出来的。）只有当出现水衰精滑、小便不禁，且并非由水湿引起时，切忌使用。这是担心它走表泄气的缘故。
茯苓有赤茯苓和白茯苓之分。赤茯苓入小肠经，白茯苓入膀胱经。白茯苓微有补益作用，赤茯苓则只止泻湿热。一主气，一主血，自然不容混淆如此。至于茯苓皮，专门治疗水肿肤胀，这是取“以皮行皮”的道理。（凡是大肿而伴有烦渴、大便闭塞、尿色红赤的，属于阳水，可用五皮散或疏凿饮子；不烦渴、大便溏薄、小便频数、尿色不红赤且不涩痛的，属于阴水，宜用实脾饮或疏气饮；腰部以上肿胀的宜用发汗法，腰部以下肿胀的宜用利小便法。）以大块、坚实、洁白的为佳。（这是因为松根的灵气凝结而成。）茯苓畏恶白蔹，畏惧地榆、秦艽、龟甲、雄黄。忌食醋。
Fuling (Poria): It can secrete and remove dampness from the Spleen and Lungs, and attack water pathogenic factors in the Liver and Stomach.
Fuling primarily enters the Spleen and Stomach meridians, and concurrently enters the Lung and Liver meridians. Its color is white, thus entering the Lung meridian; its taste is sweet, thus entering the Spleen meridian; its taste is bland, possessing a diuretic and damp-draining action. Therefore, medical texts record that it can upper-secrete dampness from the Spleen and Lungs, and lower-attack pathogenic factors of the Liver and Kidneys. Its Qi first ascends (clearing Lung Qi to transform the source), then descends (descending to promote urination). For any disease caused by water-dampness manifesting as rebellious Qi, vexation and fullness, knotting and pain below the heart, hiccups and vomiting, bitter taste in the mouth and dry tongue, edema, strangury with stagnation, worry and anger, fright and terror, as well as urine that is either obstructed or frequent (these diseases are all discussed from the perspective of being generated by water-dampness), taking Fuling will be effective. (Thus, treatment also follows the principle of removing water-dampness.)
Therefore, when added to Sijunzi Tang (Four Gentlemen Decoction), it assists Renshen (Ginseng Radix) and Baizhu (Atractylodis Rhizoma) to secrete dampness from the Spleen; when added to Liuwei Dihuang Wan (Six-Ingredient Pill with Rehmannia), it guides Zexie (Alisma Rhizome) to circulate residual pathogenic factors in the Kidney. It is the most important herb for promoting urination and removing dampness. Texts say it "strengthens the Spleen," which means that once water-dampness is removed, the Spleen naturally becomes strong. It is also said to "stabilize the Po" (The Lung stores the Po spirit), which means that once water-dampness is removed, the Po naturally becomes tranquil. Moreover, once water-dampness is removed, urination naturally opens; how could there be concern about strangury (obstructed urination)? Once water-dampness is removed, internal dampness is already eliminated; how could there still be excessive urination? Thus, once water-dampness is removed, the chest and diaphragm naturally become relaxed, and knotting, pain, vexation, and fullness do not occur; once water-dampness is removed, body fluids naturally generate, and bitter taste in the mouth and dry tongue are completely eliminated. (Thus, efficacy is also seen after water-dampness has been removed.) Only when there is deficiency of water leading to seminal emission and slippery essence, or involuntary urination, not caused by water-dampness, should it be strictly contraindicated. This is to avoid the fear of it dispersing the exterior and leaking Qi.
Fuling comes in red and white varieties. Red Fuling enters the Small Intestine meridian; white Fuling enters the Bladder meridian. White Fuling has slight tonifying properties, while red Fuling only stops diarrhea due to damp-heat. One governs Qi, the other governs Blood; they naturally cannot be confused. As for Fuling Pi (Poria Peel), it specifically treats edema and abdominal distension, based on the principle of "using peel to treat skin." (Generally, swelling accompanied by vexation and thirst, constipation, and dark urine belongs to Yang Edema, treated with Wupi San (Five-Peel Powder) or Shuozao Yin (Scouring Drink); without vexation and thirst, with loose stools, frequent urination, and urine that is not red or painful/burning, belongs to Yin Edema, treated with Shipi Yin (Spleen-Solidifying Drink) or Shuqi Yin (Qi-Circulating Drink); swelling above the waist should be treated with sweating methods, while swelling below the waist should be treated with methods to promote urination.) Large, firm, and pure white pieces are considered superior. (This is because it is formed from the spiritual energy of pine roots.) Fuling is incompatible with Bailian (Ampelopsis Radix), and fears Diyu (Sanguisorbae Radix), Qinjiao (Gentianae Macrophyllae Radix), Guijia (Testudinis Carapax et Plastrum), and Xionghuang (Realgar). Vinegar is contraindicated.