黄连，味苦，寒，可升可降，阴也，无毒。入心与胞络。最泻火，亦能入肝。大约同引
经之
药，俱能入之，而入心，尤专经也。止吐利吞酸，善解口渴。治火眼甚神，能安心，止梦遗
，定狂躁，除痞满，去妇人阴户作肿。治小儿食土作疳，解暑热、湿热、郁热，实有专功。
但亦臣使之药，而不可以为君，宜少用而不宜多用，可治实热而不可治虚热也。盖虚火宜补
，则实火宜泻。以黄连泻火者，正治也。以肉桂治火者，从治也。故黄连、肉桂，寒热实相
反，似乎不可并用，而实有并用而成功者。盖黄连入心，肉桂入肾也。凡人日夜之间，必心
肾两交，而后水火始得既济，火水两分，而心肾不交矣。心不交于肾，则日不能寐；肾不交
于心，则夜不能寐矣。黄连与肉桂同用，则心肾交于顷刻，又何梦之不安乎。
或问苦先入心，火必就燥，黄连味苦而性燥，正与心相同，似乎入心之相宜矣，何以久
服黄
连，反从火化，不解心热，而反增其焰者，何也？曰∶此正见用黄连之宜少，而不宜多也
。盖心虽属火，必得肾水以相济，用黄连而不能解火热者，原不可再泻火也。火旺则水益衰
，水衰则火益烈，不下治而上治，则愈增其焰矣，譬如釜内无水，止成焦釜，以水投之，
则热势上冲而沸腾矣。治法当去其釜下之薪，则釜自寒矣。故正治心火而反热者，必从治心
火之为安，而从治心火者，又不若大补肾水之为得。盖火得火而益炎，火得水而自息耳。
或问黄连止痢而浓肠胃，吾子略而不谈，何也？曰∶此从前《本草》各书，无不载之，
无俟
再言也。然而予之不谈者，又自有在。盖黄连非治痢之物，泻火之品也。痢疾湿热，用黄连
性燥而凉，以解湿而除热似矣。殊不如黄连独用以治痢，而痢益甚，用之于人参之中，治噤
口之痢最神；用之于白芍、当归之中，治红赤之痢最效，可借之以泻火，而非用之以止痢，
予所以但言其泻火耳。况上文曾言止吐利吞酸，利即痢也，又未尝不合言之矣。至于浓肠胃
之
说，说者谓泻利日久，下多亡阴，刮去脂膜，肠胃必薄矣，黄连既止泻利，则肠胃之薄者，
可以重浓。嗟乎！此臆度之语，而非洞垣之说也。夫黄连性燥而寒凉，可以暂用，而不可久
用。肠胃之脂膜既伤，安得一时遽浓哉。夫胃薄者，由于气血之衰，而肠薄者，由于精水之
耗。黄连但能泻火，而不能生气血、精水，吾不知所谓浓者，何以浓也。
或问黄连泻火，何以谓之益心，可见寒凉未必皆是泻药。曰∶夫君之论，是欲扬黄柏、
知母
也。吾闻正寒益心，未闻正寒益肾。夫心中之火，君火也；肾中之火，相火也。正寒益心中
之君火，非益心中之相火。虽心中君火，每藉心外相火以用事，然而心之君火则喜寒，心之
相火则喜热。以黄连治心之君火，则热变为寒。以黄连治心之相火，则寒变为热。盖君火宜
正治，而相火宜从治也。夫相火在心火之中，尚不用寒以治热，况相火在肾水之内，又乌可
用寒以治寒乎。昔丹溪用黄柏、知母，入于六味丸中
，未必不鉴正寒益心，亦可用正寒以益肾也。谁知火不可以水灭，肾不可与心并论哉。
或疑世人用黄连，不比用黄柏、知母，先生辟黄柏、知母，何必于论黄连之后，而大张
其文
澜哉？嗟乎！是有说焉，不可不辨也。夫人生于火，不闻生于寒也。以泻火为生，必变生为
死
矣。从来脾胃喜温，而不喜寒，用寒凉降火，
虽降肾火也，然胃为肾之关门，肾寒则胃寒，胃寒则脾亦寒。脾胃既寒，又何以
蒸腐水谷哉。下不能消，则上必至于不能受，上下交困，不死何待乎，又肺金之气，必夜归
于肾之中，肾火沸腾，则肺气不能归矣。然补其肾水，而益其肺金，则肾足，而肺气可复归
于肾。倘肾寒则肾火不归，势必上腾于肺，而又因肾之寒，不敢归于下，则肺且变热，而咳
嗽之症生。肺热而肾寒，不死又何待乎。慨自虚火实火、正火邪火、君火相火之不明，所以
治火之错也。夫黄连，泻实火也，补正火也，安君火也，不先将黄连之义，罄加阐扬，则虚
火、邪火、相火之道，终不明于天下。吾所以于黄连门中，痛攻黄柏、知母，使天下后世知
治火之药，不可乱用寒凉，实救其源也。
黄连，味道苦，性质寒，药势既可上升也可下降，属于阴经药物，没有毒性。进入心经和心包络经。它最擅长清泻火热，也能进入肝经。大致上，只要有引导药物到达相应经络的引经药配合，黄连都能进入各经，但进入心经的作用尤为专一。它能止住呕吐、腹泻及吞酸症状，善于解除口渴。治疗火眼（由火热之邪引起的眼部疾病）非常神奇，能安定心神，止住梦遗，平定狂躁情绪，消除痞满感，去除妇女外阴肿胀。治疗小儿因吃土导致的疳积，解除暑热、湿热、郁热，确实有独特的功效。但是，它也属于臣使类药物，不能作为君药使用，适宜少量使用而不宜多用，可以治疗实热证而不能治疗虚热证。因为虚火适宜用补法，那么实火就适宜用泻法。用黄连来泻火，是正治法。用肉桂来治火，是从治法。所以黄连和肉桂，一寒一热实际上相反，似乎不能同时使用，但实际上有同时使用而取得成功的案例。这是因为黄连入心经，肉桂入肾经。凡人在日夜之间，必须心肾相交，然后水火才能既济，如果火水分离，心肾就不相交了。心不交于肾，则白天不能安睡；肾不交于心，则夜晚不能安睡。黄连与肉桂同用，则心肾在顷刻间就能相交，又怎么会有睡眠不安呢？
有人问：苦味先入心，火性就燥，黄连味苦而性燥，正与心的特性相同，似乎适合入心，为什么久服黄连，反而从火化，不解心热，反而增加火势呢？回答说：这正好说明使用黄连应该少用，而不宜多用的道理。因为心虽然属火，但必须得到肾水的济助。使用黄连而不能解除火热者，原本就不可以再泻火了。火旺则水更加衰弱，水衰则火更加猛烈，如果不从下焦治疗而从上面治疗，就会更加增加火势。譬如锅里面没有水，只剩下烧焦的锅，往里面加水，热气就会向上冲并沸腾。治疗方法应当去掉锅下面的柴火，锅自然就会冷却。所以正治心火反而导致发热的人，不如从治心火来得安稳，而从治心火，又不若大补肾水更为得当。因为火遇到火会更加燃烧，火遇到水自然会熄灭。
有人问：黄连能止痢并增厚肠胃，我稍微略去不谈，为什么呢？回答说：这是从前《本草》各书无不记载的内容，无需再言。然而我不谈的原因，自有我的道理。因为黄连不是治疗痢疾的药物，而是泻火的药品。痢疾多由湿热引起，用黄连性燥而凉的特性，来解湿除热似乎是对的。殊不知单用黄连治疗痢疾，痢疾反而会加重；将其与人参配合，治疗噤口痢（指痢疾中饮食不进的一种重症）最为神奇；将其与白芍、当归配合，治疗红赤痢（便下脓血）最为有效。这是借黄连来泻火，而不是用它来止痢，所以我只是说它泻火罢了。况且上文曾说它能止吐利吞酸，“利”即指痢疾，也未曾不合在一起说。至于“增厚肠胃”的说法，评论者认为泻利日久，下利多亡阴，刮去了脂膜，肠胃必然变薄了，黄连既然能止泻利，那么变薄的肠胃就可以重新增厚。唉！这是主观臆测的话，而非洞察脏腑真相的说法。黄连性燥而寒凉，可以暂时使用，而不可长期使用。肠胃的脂膜既然已经受伤，怎么能一时之间迅速增厚呢？胃壁薄，是由于气血衰弱；肠壁薄，是由于精水耗损。黄连只能泻火，而不能生气血、精水，我不知道所谓的“厚”，是怎么厚的。
有人问：黄连泻火，为什么被称为益心？可见寒凉药未必都是泻药。回答说：您的论点，是想推崇黄柏、知母吧。我听说正寒之性能益心，没听说过正寒之性能益肾。心中的火，是君火；肾中的火，是相火。正寒之性益的是心中的君火，不是益心中的相火。虽然心中君火，常常借助心外的相火来发挥作用，然而心的君火喜欢寒凉，心的相火喜欢温热。用黄连治疗心的君火，则热变为寒。用黄连治疗心的相火，则寒变为热。因为君火适宜正治，而相火适宜从治。相火在心火之中，尚且不用寒凉来治热，何况相火在肾水之内，又怎可用寒凉来治寒呢？过去朱丹溪用黄柏、知母，加入六味丸中，未必不是借鉴了正寒益心的理论，也想用正寒来益肾。谁知道火不可以用水灭，肾不可以与心并论呢？
有人怀疑世人用黄连，并不比用黄柏、知母少，先生批驳黄柏、知母，何必在论述黄连之后，大肆张扬波澜呢？唉！这里有说法，不可不辨明。人生于火，没听说生于寒。以泻火为生，必定会把生变成死。从来脾胃喜欢温暖，而不喜欢寒凉，使用寒凉药降火，虽然是降肾火，但胃是肾的关门，肾寒则胃寒，胃寒则脾也寒。脾胃既已寒凉，又凭什么蒸腐水谷呢？下面不能消化，上面必然至于不能受纳，上下都陷入困境，不死还等什么？另外，肺金之气，必须在夜间回归到肾中，如果肾火沸腾，肺气就不能回归了。然而补充肾水，并益养肺金，则肾气充足，肺气可以重新回归于肾。倘若肾寒，则肾火不归，势必上腾于肺，又因为肾寒，不敢回归于下，则肺会变热，从而产生咳嗽的症状。肺热而肾寒，不死还等什么？感慨自从虚火实火、正火邪火、君火相火的概念不明确，所以治疗火证的错误由此产生。黄连，是泻实火的，补正火的，安守君火的，不先将黄连的含义彻底阐扬，那么虚火、邪火、相火的道理，终究不能在天下人面前讲清楚。所以我于黄连门类中，痛攻黄柏、知母，使天下后世知道治疗火的药物，不可乱用寒凉，这才是从根本上挽救的方法。
Huanglian (Coptidis Rhizoma), with a bitter taste and cold nature, has the property of ascending and descending, belongs to Yin, and is non-toxic. It enters the Heart meridian and Pericardium meridian. It is most effective in clearing and purging fire, and can also enter the Liver meridian. Generally, with the guidance of channel-directing herbs, it can enter various meridians, but its entry into the Heart meridian is particularly specific. It stops vomiting, diarrhea, and acid regurgitation, and effectively relieves thirst. It is miraculous in treating Huoyan (eye diseases caused by fire-heat pathogen), calms the mind, stops nocturnal emission, settles mania and restlessness, removes epigastric fullness and stuffiness, and eliminates swelling of the female external genitalia. It treats pediatric Gan syndrome (malnutrition due to dietary irregularities or parasitic infection) caused by eating soil, and resolves summerheat, damp-heat, and constrained heat, possessing unique efficacy. However, it serves as a minister or assistant herb and should not be used as a sovereign herb; it is suitable for small doses rather than large ones, can treat excess heat syndromes but cannot treat deficiency heat syndromes. This is because deficiency fire is treated by tonification, whereas excess fire is treated by purgation. Using Huanglian to purge fire is the direct treatment method (Zheng Zhi). Using Rougui (Cinnamon Twig) to treat fire is the contrary treatment method (Cong Zhi). Therefore, although Huanglian and Rougui are opposite in cold and hot nature and seem incompatible, there are cases where their combined use succeeds. This is because Huanglian enters the Heart meridian, while Rougui enters the Kidney meridian. In daily life, the Heart and Kidney must interact for Water and Fire to achieve mutual balance (Ji Ji); if Fire and Water separate, Heart-Kidney interaction ceases. If the Heart does not interact with the Kidney, one cannot sleep during the day; if the Kidney does not interact with the Heart, one cannot sleep at night. When Huanglian and Rougui are used together, Heart and Kidney interact instantly, ensuring peaceful sleep.
One might ask: Bitter flavors first enter the Heart, and Fire tends towards dryness. Huanglian is bitter and dry in nature, which aligns with the Heart's characteristics, making it seemingly suitable for the Heart. Why does long-term consumption of Huanglian lead to transformation into fire, failing to relieve Heart heat but instead increasing the flame? The answer is that this precisely illustrates why Huanglian should be used in small doses and not in large amounts. Although the Heart belongs to Fire, it requires the assistance of Kidney Water. If Huanglian fails to resolve heat-fire, further purging of fire is inappropriate. Excessive Fire leads to further depletion of Water, and depleted Water leads to intensified Fire. Treating from above rather than below only increases the flame. For example, if a pot has no water, it becomes scorched; adding water causes steam to rush upward and boil. The correct treatment is to remove the firewood beneath the pot, cooling it naturally. Thus, for those whose direct treatment of Heart fire results in increased heat, contrary treatment is safer; and among contrary treatments, greatly tonifying Kidney Water is most appropriate. Fire intensifies when meeting Fire, but extinguishes when meeting Water.
One might ask: Huanglian stops dysentery and thickens the intestines and stomach, yet you briefly omit discussing this. Why? I reply: Previous Materia Medica texts all record this, requiring no further elaboration. However, my reason for omitting it is distinct. Huanglian is not a drug for treating dysentery per se, but a product for purging fire. Dysentery is often caused by damp-heat; using Huanglian’s dry and cool nature to resolve dampness and clear heat seems logical. Yet, using Huanglian alone for dysentery may worsen the condition. Combined with Renshen (Ginseng Radix et Rhizoma), it is miraculous for Jin Kou Li (dysentery with inability to eat); combined with Baishao (Paeoniae Radix Alba) and Danggui (Angelicae Sinensis Radix), it is most effective for Hong Chi Li (dysentery with bloody stools). Here, Huanglian is borrowed to purge fire, not primarily to stop dysentery. Hence, I only mention its fire-purging capability. Moreover, earlier I mentioned stopping vomiting, diarrhea, and acid regurgitation; "Li" refers to dysentery, so it was implicitly included. Regarding the claim that it "thickens the intestines and stomach," commentators argue that prolonged diarrhea depletes Yin, scraping away mucosal membranes, thinning the gut; since Huanglian stops diarrhea, the thinned gut can thicken again. Alas! This is speculative reasoning, not an insight into internal organs. Huanglian is dry and cold/cool; it can be used temporarily but not long-term. Once intestinal mucosa is damaged, how can it thicken instantly? A thin stomach wall results from Qi and Blood deficiency; a thin intestine results from Essence and Water depletion. Huanglian can only purge fire, not generate Qi, Blood, Essence, or Water. I do not understand how it achieves "thickening."
One might ask: Huanglian purges fire, yet is said to benefit the Heart. This shows that cold-natured herbs are not necessarily purgatives. I reply: Your argument aims to promote Huangbai (Phellodendri Cortex) and Zhimu (Anemarrhenae Rhizoma). I have heard that truly cold herbs benefit the Heart, but never that they benefit the Kidney. The Fire in the Heart is Sovereign Fire (Jun Huo); the Fire in the Kidney is Ministerial Fire (Xiang Huo). Truly cold herbs benefit the Sovereign Fire in the Heart, not the Ministerial Fire. Although Sovereign Fire relies on external Ministerial Fire for function, Sovereign Fire prefers cold, while Ministerial Fire prefers warmth. Using Huanglian to treat Sovereign Fire transforms heat into cold; using it to treat Ministerial Fire transforms cold into heat. Sovereign Fire should be treated directly, while Ministerial Fire should be treated contrarily. If Ministerial Fire within the Heart does not use cold to treat heat, how much less should Ministerial Fire within Kidney Water use cold to treat cold? Zhu Danxi used Huangbai and Zhimu in Liuwei Dihuang Wan, likely inspired by the idea that truly cold herbs benefit the Heart and could thus benefit the Kidney too. Who knew that Fire cannot be extinguished by Water, and the Kidney cannot be equated with the Heart?
One might doubt: People use Huanglian as much as Huangbai and Zhimu. Why do you criticize Huangbai and Zhimu so extensively after discussing Huanglian? I reply: There is a rationale that must be clarified. Humans are born of Fire, not Cold. Living by purging Fire turns life into death. The Spleen and Stomach prefer warmth and dislike cold. Using cold herbs to reduce Fire, even if targeting Kidney Fire, affects the Stomach, which is the gatekeeper of the Kidney. Kidney cold leads to Stomach cold, which leads to Spleen cold. With cold Spleen and Stomach, how can food be steamed and rotted (digested)? Failure to digest below leads to inability to receive food above. Both upper and lower systems are distressed; death is imminent. Furthermore, Lung Metal Qi returns to the Kidney at night. If Kidney Fire boils, Lung Qi cannot return. Tonifying Kidney Water and benefiting Lung Metal allows Lung Qi to return. If the Kidney is cold, Fire does not return, rising to the Lung. Due to Kidney cold, it dares not descend, causing Lung heat and cough. Lung heat with Kidney cold leads to death. Since the distinctions between deficiency/excess fire, righteous/pathogenic fire, and Sovereign/Ministerial fire are unclear, errors in treating fire arise. Huanglian purges excess fire, supplements righteous fire, and calms Sovereign fire. Without thoroughly elucidating Huanglian, the principles of deficiency, pathogenic, and Ministerial fire will remain obscure. Thus, I vigorously critique Huangbai and Zhimu in the Huanglian section, warning future generations against indiscriminate use of cold-natured herbs for treating fire, thereby addressing the root cause.