Library

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.