古名通脱木
轻、通、利水、退热
色白气寒，体轻味淡。气寒则降，故入肺经，引热下行而利小便；味淡则升，故入胃经
，通气上达而下乳汁。治五淋水肿，目昏耳聋，鼻塞失音（淡通窍，寒降火，利肺气），退
热催生。
通，利水，泻膀胱火
甘淡微咸。入膀胱，利小便，泻肾经之火邪，功专利湿行水。
治消渴痰饮，呕吐泻痢，肿胀水痞，香港脚疝痛，淋沥阴汗（阴间有汗），尿血泄精（既
利水而又止泄精，何也？此乃湿热为病。不为虚滑者言也，虚滑则当用补涩之药），湿热之
病。
湿热既除，则清气上行。又能养五脏，益气力，起阴气，补虚损，止头旋，有聪耳、明
目之功（脾胃有湿热，则头重耳鸣目昏。渗去其湿，则热亦随去，土乃得令，而精气上行。
故《本经》列之上品，云聪耳明目，而六味丸用之，今人多以昏目疑之）。多服昏目（小便
过利，而肾水虚故也。眼中有水，属膀胱，过利则水涸而火生。张仲景八味丸用泽泻，寇宗
谓其接引桂附入肾经。李时珍曰∶非接引也，乃取其泻膀胱之邪气也。古人用补药，必兼
泻邪，邪去则补药得力，一阖一辟，此乃玄妙。后人不知此理，专一于补，必致偏胜之患矣。
王履曰∶地黄、山茱、茯苓、丹皮，皆肾经药，桂、附右肾命门之药，何待接引乎？钱仲阳
谓∶肾为真水，有补无泻。或云脾虚肾旺，故泻肾扶脾，不知肾之真水不可泻，泻其伏留之
邪耳！脾喜燥，肾恶燥，故兼补为难。易老云∶去脬中留垢，以其微咸能泻伏水故也。昂按∶
六味丸有熟地之温，丹皮之凉，山药之涩，茯苓之渗，山茱之收，泽泻之泻。补肾而兼补脾，
有补而必有泻，相和相济，以成平补之功，乃平淡之神奇，所以为古今不易之良方也。即有
加减，或加紫河车一具，或五味、麦冬、杜仲、牛膝之类，不过一二味，极三四味而止。今
人或疑泽泻之泻而减之，多拣本草补药，恣意加入，有补无泻。且客倍于主，责成不专，而
六味之功，且退处于虚位，失制方配合之本旨矣，此近世庸师之误也）。
盐水拌，或酒浸用。忌铁。
通草，古称通脱木。
其性轻、能通利、利水、退热。
色白气寒，质地轻而味道淡。气寒则下行，所以入肺经，引导热邪下行从而通利小便；味淡则上行，所以入胃经，通气上达从而下注乳汁。治疗五淋（五种淋证）和水肿，目昏耳聋，鼻塞失音（因其味淡能通窍，性寒能降火，利肺气），退热催生。
泽泻，功效为利水，泻膀胱之火。
味甘、淡，微咸。入膀胱经，利小便，泻肾经的火邪，功效专门在于利湿行水。
治疗消渴（糖尿病类症状）、痰饮，呕吐腹泻痢疾，肿胀水痞，脚气疝痛，淋沥阴汗（阴部有汗），尿血泄精（既能利水又能止泄精，为什么呢？这是因为湿热导致的疾病。不是针对虚滑证而言的，虚滑证应当使用补涩的药物）。这是湿热类的疾病。
湿热既已清除，清气便会上行。又能滋养五脏，益气力，起阴气，补虚损，止头晕，具有聪耳、明目的功效（脾胃若有湿热，就会头重耳鸣目昏。渗去湿气，热邪也随之而去，脾土功能恢复正常，精气得以向上输布。所以《神农本草经》将其列为上品，说它能聪耳明目，而六味地黄丸中使用了它，现在很多人因为担心它导致目昏而怀疑它）。多服用会导致目昏（因为小便过度通利，导致肾水亏虚的缘故。眼睛中的水液归属膀胱，过度利水则水液枯竭而生火。张仲景在八味丸中使用泽泻，寇宗奭认为它是引导桂枝、附子进入肾经。李时珍说：并非引导，而是取其泻除膀胱邪气的作用。古人使用补药，必定兼用泻邪药，邪气去除则补药才能得力，一阖一辟，这是玄妙之处。后人不懂这个道理，专门一味进补，必然导致偏胜的祸患。王履说：地黄、山茱萸、茯苓、牡丹皮，都是肾经的药，桂枝、附子是右肾命门的药，哪里需要引导呢？钱乙说：肾是真水，只有补没有泻。有人说脾虚肾旺，所以泻肾扶脾，不知道肾的真水不可泻，只是泻除潜伏留滞的邪气罢了！脾喜欢燥，肾厌恶燥，所以同时兼顾补肾很难。易老说：去除膀胱中的积垢，因为它味微咸能泻伏留之水。汪昂按语：六味丸中有熟地黄的温，牡丹皮的凉，山药的涩，茯苓的渗，山茱萸的收，泽泻的泻。补肾而兼补脾，有补必有泻，相互调和济助，以成就平补的功效，这是平淡中的神奇，所以是古今不变的良方。即使有加减，或者加紫河车一个，或者五味子、麦冬、杜仲、牛膝之类，不过一二味，极三四味而止。现在的人往往怀疑泽泻的泻作用而减去它，大量挑选本草中的补药，肆意加入，只补不泻。而且客药倍数超过主药，责任不专，六味丸的功效，反而退居虚位，失去了制方配合的本意，这是近代庸医的错误）。
用盐水拌，或用酒浸泡后使用。忌铁器。
Tongcao, anciently known as *Tongduomu* (Acanthopanax gracilistylus stem).
Its properties are light, penetrating, diuretic, and heat-clearing.
Its color is white, its nature is cold, its texture is light, and its taste is bland. Its cold nature descends, so it enters the Lung Meridian, guiding heat downward to promote urination; its bland taste ascends, so it enters the Stomach Meridian, promoting Qi circulation upwards to facilitate lactation. It treats five types of strangury (Wu Lin) and edema, blurred vision, deafness, nasal congestion, and loss of voice (due to its blandness opening orifices, coldness descending fire, and benefiting Lung Qi), clears heat, and induces labor.
Zexie (Alisma Rhizome) penetrates, promotes urination, and drains Bladder Fire.
Its taste is sweet, bland, and slightly salty. It enters the Bladder Meridian, promotes urination, drains Fire pathogenic factors from the Kidney Meridian, and its efficacy specializes in dispelling dampness and moving water.
It treats thirst (Xiao Ke), phlegm-fluid retention, vomiting, diarrhea, dysentery, swelling, water-type palpitations (Shui Pi), podagra (Hong Kong Jiao - gouty arthritis of the foot), hernia pain, dribbling strangury, and scrotal sweating (Yin Han - sweating in the genital area), hematuria, and seminal emission (it can both promote urination and stop seminal emission; why? This is because the disease is caused by Damp-Heat. This does not refer to deficiency-type sliding/leakage; for deficiency-sliding, astringent and tonifying herbs should be used). It treats diseases of Damp-Heat.
Once Damp-Heat is eliminated, clear Qi ascends. It can also nourish the Five Zang Organs, benefit Qi and strength, raise Yin Qi, tonify deficiency and damage, stop dizziness, and has the effects of improving hearing and clarifying vision (If there is Damp-Heat in the Spleen and Stomach, there will be heavy head, tinnitus, and blurred vision. By渗 [shèn] - leaching out dampness, heat goes with it, Earth [Spleen] functions normally, and Essence-Qi ascends. Thus, *Shennong Ben Cao Jing* lists it in the Superior Grade, stating it improves hearing and vision. It is used in Liuwei Dihuang Wan, yet many today doubt it due to fears of blurring vision). Excessive consumption causes blurred vision (because excessive urination depletes Kidney Water. Fluids in the eyes belong to the Bladder; excessive draining leads to dryness and generation of Fire. Zhang Zhongjing uses Zexie in Bawei Wan. Kou Zongshi believed it guides Guizhi and Fuzi into the Kidney Meridian. Li Shizhen said: It is not for guidance, but to drain pathogenic factors from the Bladder. Ancients using tonics always combined them with draining herbs; once pathogens are removed, tonics work effectively. Closing and opening, this is the profound mystery. Later generations did not understand this, focusing solely on tonification, inevitably leading to imbalance. Wang Lü said: Shudi, Shanzhuyu, Fuling, Mudanpi are all Kidney Meridian herbs; Guizhi and Fuzi are Right Kidney Mingmen herbs; what need is there for guidance? Qian Yitian said: The Kidney is True Water, having only tonification without draining. Some say Spleen deficiency and Kidney excess require draining the Kidney to support the Spleen, not knowing that True Water of the Kidney cannot be drained, only latent pathogens. Spleen likes dryness, Kidney dislikes dryness, so combining tonification is difficult. Yi Lao said: It removes residue in the bladder because its slight saltiness drains stagnant water. Ang notes: Liuwei Dihuang Wan contains the warmth of Shudi, coolness of Mudanpi, astringency of Shanyao, permeability of Fuling,收敛 (shōu liǎn) - gathering/astringency of Shanzhuyu, and draining action of Zexie. Tonifying the Kidney while supporting the Spleen, having both tonification and draining, harmonizing and assisting each other to achieve balanced tonification, this is the miracle in plainness, hence an unchanging excellent prescription since antiquity. Even with modifications, adding one placenta (Ziheche), or Wuweizi, Maidong, Duzhong, Niuxi, etc., no more than one or two ingredients, at most three or four. Modern people often doubt the draining action of Zexie and remove it, arbitrarily adding various tonic herbs from materia medica, tonifying without draining. Moreover, if accessory herbs exceed main herbs in dosage, responsibility is not focused, and the efficacy of Liuwei Dihuang Wan retreats to a secondary position, losing the original intent of formula composition. This is the error of mediocre physicians in recent times).
Use after mixing with salt water or soaking in wine. Avoid iron.