Fire of Water: Huang Lian 黃連

味苦皆屬水，地黃為之主，黃芩為木，黃連為火，白術為土，竹葉為金。

All bitter belongs to water; it is governed by Dihuang, Huangqin is wood, Huanglian is fire, Baizhu is earth, and Zhuye is metal.

Huanglian 黃連 (Coptis root) is the Fire of Water.

Among the most bitter substances in the materia medica, Huanglian has famously been described as being “more bitter than widow’s tears.” Its pronounced bitter flavor is so great that when it is added to decoctions with other herbs, even just a few grams of Huanglian can be enough to dominate the flavor of an entire formula.

Along with its yellow siblings, Huangqin and Huangbai, Huanglian clears heat, drains toxicity, and drains dampness. Huangqin’s action is ascribed to the upper burner, Huanglian to the middle burner, and Huangbai to the lower burner. In particular, Huanglian is often said to have an affinity to both the Stomach and the Large Intestines, making it in some sense a Yangming herb.

However, the fact that Huanglian is classified in the Tang Ye Jing as the Fire of Water implies that its action is not only confined to the middle burner.

This idea is supported by the Shen Nong Ben Cao Jing, which describes the action of Huanglian in this way:

黃連 味苦，寒。主熱氣，目痛，眥傷，泣出，明目，腸澼，腹痛，下痢，婦人陰中腫痛。久服令人不忘，一名王連。

Huanglian’s flavor is bitter [and its nature] is cold. It governs heat qi, eye pain, damage to the canthii, tears pouring out, brightening the eyes, intestinal afflux, abdominal pain, diarrhea, swelling and pain within the female genitalia. Protracted taking improves the memory; another name is Wanglian [literally, “King (Huang) Lian”, or perhaps, “King of succession / carrying on”].

Huanglian’s ability to improve memory suggests it has an effect not only on the digestive organ networks, but also on consciousness, through its ability to drain fire. In particular, this implies that Huanglian has an affinity to the Heart, which belongs to Imperial Fire and is the seat of consciousness. The fact that it can treat damage to the canthii of the eyes also suggests a Heart affinity; the canthii of the eye are red (the color of Fire) and belong to the Heart in the "Five Wheels" diagnosis of Chinese Medical Ophthalmology.

There are also sound theoretical reasons why an herb that has the ability to clear heat in the Stomach (and the intestines, part of the Yangming “Stomach Family” 胃家 weijia) would also affect the Heart. Although it is now classified as a Fire organ, it has been noted by Heiner Fruehauf and other scholars that initially the Heart was classified as an Earth organ, like the Stomach. This was no doubt due to the central role played by the Heart as the Emperor organ. And when considering the circadian rhythm of yingqi through the channels and organs, the Foot Yangming Stomach and the Hand Jueyin Pericardium are clock opposites, suggesting a close relationship between the Heart (Protector) and the Stomach.

Huang Lian, c/o Kamwo Herbs

These cosmological connections are also describing physiological relationships. When there is excessive heat in the Stomach, this can rise to harass the Heart, resulting in vexation, insomnia and other psycho-emotional symptoms as well as physical symptoms such as bleeding. From a biomedical perspective as well, the adjacent structures of the anatomical heart and stomach can make it clinically challenging to differentiate between acid reflux and a heart attack.

Understanding these rich symbolic connections between the Stomach and the Heart help us to understand how Zhang Zhongjing uses Huanglian in his formulas. It is used in formulas that primarily treat damp heat in the Small Intestine (which from a Zang Fu perspective also belongs to Fire), such as Gegen Huanqin Huanglian Tang 葛根黃苓黃連湯.

However, Huanglian also features heavily in formulas that treat symptoms such as “vexation in the heart with insomnia” (心中煩,不得臥), as in Huanglian Ejiao Tang 黃連阿膠湯. In fact, Huanglian is used in its greatest dose in Huanglian Ejiao Tang, which clearly emphasizes its ability to drain fire from the Heart in Yin Deficiency, when paired with yin enriching herbs such as Ejiao and Shaoyao.

In other cases, as in the Xie Xin Tang 瀉心湯 formulas, Huanglian is used to treat both digestive symptoms as well as vexation, indicating that heat is harassing the Heart. In the Xie Xin formulas, the character xin 心 which normally indicates the Heart organ can be seen as a kind of shorthand for the region below the Heart, the xin xia 心下 or epigastrium. This usage again reflects the close relationship between the Stomach and the Heart, and the ability of Huanglian to treat both organ networks.

The Xie Xin Tang formulas are all treating a pattern of stagnant qi in the epigastrium, resulting in blockage and fullness in the epigastrium. This particular kind of stagnation is known as a glomus or pi 痞 disrupts the normal qi dynamic of the digestive symptom, resulting in heat in the Stomach and cold in the Spleen. The heat in the Stomach can in turn harass the Heart, resulting in symptoms of vexation, as in the symptom picture of Gancao Xie Xin Tang 甘草瀉心湯 described in Line 158 of the Shang Han Lun.

In all of these formulas, it should be noted that Huanglian is paired with fellow Water class herb Huangqin, which as discussed previously brings Water to Wood by cooling Ministerial Fire in the Gallbladder. Huanglian brings Water to Fire by treating the Heart, understood both as the Heart organ network and more broadly as the epigastrium, which implicates the Stomach and digestive organs as well as the Heart.

Together this combination of Huanglian and Huangqin is able to strongly drain fire and resolve stagnation in the epigastrium. This synergy can be understood also in terms of the close association between Wood and Fire in the generating cycle, and also the relationship of Wood and Fire in controlling (Wood) and generating (Fire) Earth.

Hopefully this examination of formula uses shows how the classification of Huanglian as the Fire of Water symbolically represents the full range of function of Huanglian. The close association between the Heart and the Stomach is implicated in many conditions we commonly encounter in the clinic, such as insomnia.