bubble_chart Concept

Cracks appearing on the tongue, with shapes such as horizontal, vertical, herringbone, river-shaped, and well-shaped, are collectively referred to as tongue fissures.

Tongue fissures, known as "tongue rupture" by Sun Si-miao in the Tang Dynasty, as mentioned in Qianjin Fang in the chapter on heart pulse theory: "When the viscera are solid, ... the flesh is hot, the mouth opens, and the tongue ruptures."

From clinical observations, tongue fissures generally indicate a heat pattern, but the presence or absence of coating and the different colors of the tongue coating can greatly vary the primary disease. This section discusses tongue fissures mainly focusing on the presence or absence of coating as a key point for disease differentiation.

bubble_chart Pattern Analysis

1. Yin Deficiency with Fluid Depletion︰The tongue shows fissures, is without coating, the tongue texture is deep red or crimson with little moisture, dry mouth, emaciation, vexing heat in the chest, palms, and soles, or there may be bleeding or macules, and the pulse is thin and rapid. This often occurs during the peak stage of illness, commonly seen in the late stage [third stage] of warm febrile disease, due to prolonged retention of pathogenic heat, blazing heat toxin, scorching body fluids, and severe damage to yin fluids; or due to certain chronic sexually transmitted diseases that persist untreated, zang-fu organ depletion, damage to yin and consumption of fluids; or due to inherent yin deficiency combined with mistakenly consuming warm and drying substances, leading to damage to yin. All these factors can result in a fissured tongue. Liang Yu-yu's "Differentiation and Correction of Tongue Diagnosis" states: "A fissured tongue is due to scorched and withered blood, caused by untreated internal heat and blazing fire toxin," and "it can also result from mistakenly consuming hot foods or mistakenly taking warming and tonifying pungent and drying medicines that scorch true yin." The key points of differentiation are: a fissured tongue without coating, deep crimson or glossy red tongue texture, accompanied by other symptoms of yin deficiency with internal heat (dry mouth, night sweats, vexing heat in the chest, palms, and soles, and a thin, rapid pulse). As for treatment, "Song Compendium of Tongue Differentiation" once summarized: "Grooves in the tongue—enrich yin for yin deficiency, clear heat if there is heat." The prescription chosen is Fluid-Increasing Decoction to enrich yin and clear heat. If accompanied by bleeding or macules, it can be combined with Rhinoceros Horn and Rehmannia Decoction. However, this pattern differs when seen during the peak stage of pathogenic heat blazing in the course of external-contraction febrile disease. The mechanism of disease is pathogenic heat transmitting internally to yangming, binding in the stomach and intestines, transforming into dryness and becoming excess, consuming body fluids, and leading to a fissured tongue. "Treatise on Cold Damage," line 181, states: "In taiyang disease, if sweating, purging, or promoting urination are employed, this exhausts fluids, dries the stomach, and thereby transfers to yangming, with no bowel movement, internal excess, and difficulty in defecation—this is called yangming." This explains that taiyang disease transfers to yangming due to fluid damage. If the tongue shows fissures, it is a sign of yin fluid exhaustion. This differs from a fissured tongue caused purely by yin deficiency and fluid depletion—the former involves excess pathogens damaging yin.
2. Yangming Excess Heat︰The tongue shows fissures with a yellow and rough coating, accompanied by fever, sweating, aversion to heat, dysphoria, thirst with a desire to drink, severe constipation, abdominal distension and fullness that is hard and tender to pressure, and even delirious speech or floccillation. The pulse is surging and rapid or deep and replete. This contrasts with cases where deficiency predominates and pathogenic factors are minimal. The key diagnostic points for this syndrome are: fissured tongue with a coating that is yellow and rough, dry and rough to the touch with scant moisture, along with symptoms of dryness-heat binding internally in the intestines and stomach (constipation, abdominal distension and fullness, and tenderness to pressure). Treatment should focus on emergent purgation to preserve yin, akin to taking away firewood from under a cauldron. The recommended formula is Major Purgative Decoction.

Additionally, it is important to note that healthy individuals may occasionally have tongue fissures, which can be either congenital or long-standing. However, if the person is otherwise normal, this should not be considered a pathological condition. The characteristics of such tongue fissures include: the tongue texture appears a healthy flesh-red color, neither swollen nor shrunken, neither aged nor tender, with a thin, white, and moist coating. The body fluids in the mouth are normal, and the person experiences no discomfort or other symptoms.

bubble_chart Documentation

1. 《Tongue Differentiation》: "A dry and cracked white coating indicates cold damage disease with cold in the chest and heat in the dantian. The white coating on the tongue is due to excessive sweating damaging the nutrient aspect, leading to a lack of fluid on the tongue and thus dryness and cracking. There is no substantial internal heat, so the coating does not turn yellow or black. It is appropriate to use Minor Bupleurum Decoction with Mirabilite to gently promote bowel movement."
2. 《Shenyan Medical Tongue Mirror》: "Regardless of whether the tongue coating is white, red, yellow, or black, if there are cracks resembling the characters '川', '爻', or '人', or if there are straight grooves, it is often caused by individuals with substantial heat mistakenly consuming warming and tonifying decoctions, leading to heat and fire contending within the organs. Although Major Purgative Decoction can expel toxins, it cannot cool and penetrate the intestines and stomach. It is advisable to alternate between White Tiger Decoction and Chengqi Decoction."