古名通草。轻、通、行水、泻心小肠火。
辛甘淡平。轻虚。上通心包。降心火，清肺热。（心火降则肺热清。）化津液。（肺为水
源、
肺热清则津液化、水道通。）下通大小肠膀胱。导诸湿热由小便出。（凡利小便者、多不利大
便、以小水愈通、大便愈燥也、木通能入大肠、兼通大便。东垣曰∶肺受热邪、津液气化
之源绝、则寒水断流、膀胱受湿热癃闭约束、则小便不通、宜此治之、朱二允曰∶火在上则
口燥眼赤鼻干，在中则心烦呕哕浮肿，在下则淋秘足肿、必借此甘平之性、泻诸经之火、火
退则小便自利、便利则诸经火邪皆从小便而下降矣。君火宜木通、相火宜泽泻、利水虽同
、所用各别。）通利九窍。血脉关节。治胸中烦热。遍身拘痛。（杨仁斋云∶遍身隐热疼痛、
拘急足冷、由伏热伤血、宜木通以通心窍、则经络自流行也。）大渴引饮。（中焦火。）淋沥
不通。（下焦火、心与小肠相为表里、心移热于小肠则淋秘。）耳聋泄肾火、通窍、目眩。口
燥舌干。（舌为心苗。）喉痹咽痛。（火炎上焦。）鼻 （热壅清道、则气窒不通。）失音。（清
金。）脾热好眠。（脾主四肢、倦则好眠、心为脾母、心热清则脾热亦除。）除烦退热。止痛
排
（火不亢于内、气顺血行、则经调有准、乳汁循常。）精滑气弱。
内无湿热及妊娠者。均忌。色白而梗细者佳。藤有细孔，两头皆通。（故通窍。金疮 折
、酿酒日饮、亦治鼠漏。）
Originally named Tongcao. It is light, unblocking, promotes water metabolism, and drains the fire of the Heart and Small Intestine.
Pungent, sweet, and bland in taste; neutral in nature. Light and void in texture. It ascends to unblock the Pericardium (Pericardium Meridian of Hand-Jueyin), descends Heart Fire, and clears Lung Heat. (When Heart Fire descends, Lung Heat is cleared.) It transforms body fluids. (The Lung is the source of water; when Lung Heat is cleared, body fluids are transformed, and water passages become unobstructed.) It descends to unblock the Large Intestine, Small Intestine, and Bladder, guiding damp-heat from various sources out through urination. (Generally, herbs that promote urination do not facilitate bowel movements, as increased urine output leads to drier stools; however, Mutong enters the Large Intestine and also facilitates bowel movements. Li Dongyuan stated: When the Lung is affected by heat pathogens, the source of fluid transformation and qi movement is cut off, leading to a cessation of water flow; if the Bladder is constrained by damp-heat causing retention or difficulty in urination, this herb is suitable for treatment. Zhu Eryun stated: Fire above causes dry mouth, red eyes, and dry nose; fire in the middle causes mental restlessness, vomiting, hiccups, and edema; fire below causes strangury, urinary retention, and swollen feet. One must rely on its sweet and neutral nature to drain fire from all meridians. When fire subsides, urination becomes free; with free urination and defecation, fire pathogens from all meridians descend via urine. For Sovereign Fire, Mutong is appropriate; for Ministerial Fire, Ze Xie is appropriate. Although both promote water metabolism, their applications differ.) It unblocks the nine orifices, unblocks blood vessels and joints, treats chest irritability and heat, and generalized stiffness and pain. (Yang Renzhai said: Generalized dull heat and pain, stiffness, and cold feet are caused by latent heat damaging the blood; Mutong should be used to unblock the Heart orifices, so that meridians will naturally circulate freely.) Profound thirst with excessive drinking. (Due to Middle Jiao fire.) Strangury with incomplete emptying. (Due to Lower Jiao fire; the Heart and Small Intestine are exterior-interior related; when Heart heat transfers to the Small Intestine, it causes strangury and retention.) Deafness (drains Kidney fire), unblocks orifices, vertigo, dry mouth and tongue. (The tongue is the sprout of the Heart.) Pharyngolaryngeal obstruction and sore throat. (Fire flares up to the Upper Jiao.) Nasal congestion (Heat obstructs the clear pathways, causing Qi stagnation and blockage). Aphonia (Clears Metal/Lung). Spleen heat with propensity to sleep. (The Spleen governs the four limbs; fatigue leads to sleepiness; the Heart is the mother of the Spleen; when Heart heat is cleared, Spleen heat is also eliminated.) Relieves irritability and reduces fever, stops pain, and expels pus. (When fire does not hyperactivity internally, Qi flows smoothly and Blood moves, then meridians regulate properly, and milk flows according to normal channels.) Seminal emission and Qi deficiency.
Contraindicated for those without damp-heat internally and for pregnant women. Those that are white in color with thin stems are superior. The vine has fine pores, open at both ends. (Thus it unblocks orifices. For metallic wounds and fractures, brewing wine and drinking daily can also treat scrofula/fistula.)