bubble_chart Concept

Tongue coating that is white and greasy refers to a layer of white, turbid, greasy coating on the surface of the tongue. The texture of the coating is dense, with fine particles that are not easily scraped off.

White greasy coating is not mentioned in the "Treatise on Cold Damage Diseases." In the section on Yangming disease in the "Yangming Chapter," it states: "In Yangming disease, with hardness and fullness in the hypochondrium, constipation, vomiting, and a white coating on the tongue, Minor Bupleurum Decoction may be administered." Minor Bupleurum Decoction This likely refers to a white, slippery coating.

Scholars of warm diseases have begun to pay more attention to the study of white greasy coating. Xingse Waizhen Jianmo states, "Latent pathogens and seasonal pathogens both arise from within and often involve dampness. Therefore, at the onset, there is already a white coating on the tongue, which is thick rather than thin, greasy rather than slippery, or coarse like accumulated powder." This explains that white greasy coating is often seen in cases of latent pathogens.

White greasy coating and white curdy coating, although both have a thick texture, are different. Curdy coating has coarse particles that are easily scraped off, while greasy coating has fine particles that cling to the tongue surface and are not easily wiped away. This is how they are distinguished.

In normal individuals, after consuming milk or soy milk, a white greasy tongue coating may appear, which is considered a stained coating or false coating and is not indicative of a pathological condition.

bubble_chart Pattern Analysis

1. External Contractioncold-dampness︰The tongue coating is thin, white, and greasy, with aversion to cold accompanied by fever, headache with a distending sensation as if wrapped, heavy and painful body, absence of sweating, and a floating, tight pulse. The syndrome arises from exposure to cold after sweating, or being exposed to wind after bathing, or wading in water or getting caught in rain, or walking in the morning dew or night chill, leading to the invasion of cold-dampness pathogens. The defensive yang is obstructed; cold manifests as a white color, while dampness results in a greasy coating. Since the cold-dampness is in the exterior, the tongue coating appears thin, white, and greasy, with no change in the tongue texture. Aversion to cold with fever, heavy-headedness, body pain, absence of sweating, and a floating, tight pulse are all signs of wind-cold binding the exterior. Tongsu Shanghan Lun states in "Six-Channel Tongue Coatings": "It must be white, floating, slippery, and thin, and the coating returns immediately after being scraped off—this indicates the invasion of cold pathogens in the Greater Yang channel's exterior pattern." Here, "white, floating, slippery, and thin" refers to a thin, white, greasy coating, signifying the invasion of cold-dampness in the Greater Yang channel's exterior pattern. The treatment should focus on warming and dispersing cold-dampness, and the formula of choice is Notopterygium Overcoming Dampness Decoction.
2. Dampness Obstructing the Membrane Source︰The tongue coating is white, thick, greasy, and dry, or thick like accumulated powder; the tongue texture is red. Symptoms include fever and chills, body aches with sweating, heavy and sluggish limbs, nausea, vomiting, abdominal distension, and fullness, with a slow pulse. The condition arises from exposure to dampness-heat pathogens or may be caused by internal accumulation of dampness turbidity combined with external pathogenic invasion. As Xue Sheng-bai stated: "Taiyin internal damage leads to stagnation of dampness and fluids, and when an intruding pathogen arrives, internal and external factors interact, resulting in dampness-heat disease." Dampness-heat moves from the exterior to the interior, accumulating and lurking in the membrane source, causing yang qi to stagnate and dampness turbidity to rise, hence the white, greasy tongue coating. Its characteristics include a white, greasy, dry, and thick coating or a coating as white as accumulated powder, accompanied by aversion to cold with fever, body aches with sweating, nausea, vomiting, abdominal distension, and fullness—signs of pathogens lingering between the exterior and interior. Treatment should focus on resolving dampness, dispelling turbidity, and clearing heat. Recommended formulas are the Membrane-Source-Opening Decoction or Lei's method of opening onto the pleurodiaphragmatic interspace (Shibing Lun).
3. Internal Retention of Water and Fluid︰The tongue coating is white, greasy, and watery-smooth; the tongue texture is bluish-purple; the complexion is pale or dull; symptoms include vertigo, mental fatigue, cold limbs, nausea with clear saliva, epigastric and abdominal distension and fullness that improves with warmth, absence of thirst, or thirst without desire to drink, scanty urine, and a deep, slow pulse. This condition is often caused by insufficient spleen yang leading to internal retention of water and fluids. The tongue coating is white, thick, greasy, and watery-smooth, resembling thick soybean milk residue; the tongue texture is bluish-purple. During diagnosis, signs of internal retention of pathogenic fluids may be observed, such as epigastric and abdominal distension and fullness, anorexia, reversal cold of the limbs, vomiting of clear water and phlegm-saliva, and a deep, slow pulse. *The Differentiation of Tongue Appearances* states: "A white, thick, powdery, moist, greasy, and slippery coating that can be slightly scraped off but quickly accumulates again, resembling the texture of flour mixed with water, indicates interior cold and damp stagnation. Use Caoguo to revive spleen yang, so that the earth's qi rises, and the white coating in the sky can be eliminated." Treatment should focus on warming yang, reviving the spleen, and promoting water metabolism. The recommended formula is Spleen-Warming Decoction.

The symptom of a white and greasy tongue coating has been considered by many medical practitioners throughout history to indicate dampness, phlegm, and cold. The "Guide to Tongue Differentiation" states: "A white, slippery, and greasy coating indicates damp turbidity and phlegm. A thick, slippery, and greasy coating indicates damp phlegm and cold." However, the location where the pathogenic factors linger differs, leading to varying main symptoms. In cases of external contraction of cold-dampness, the pathogenic factors are on the surface, and the tongue coating will be thin, white, slippery, and greasy, accompanied by symptoms of cold-dampness binding the exterior. In cases of dampness obstructing the membrane source, the pathogenic factors reside between the exterior and interior, and the tongue coating will be white, thick, greasy, and dry, or like accumulated powder, with a slightly red tongue texture, accompanied by symptoms of dampness obstructing and yang qi failing to extend. In cases of cold fluid retention internally, the pathogenic factors are hidden within the zang-fu organs, and the tongue coating will be white, thick, greasy, and watery-slippery, with a bluish-purple tongue texture, accompanied by symptoms of fluid retention. These three syndromes can be easily distinguished based on the characteristics of the tongue coating and their accompanying symptoms.

bubble_chart Documentation

1. "On Cold Damage Diseases: Discussion and Differentiation of Taiyang Disease Pulse Signs and Treatment Below": "If there is a condition resembling thoracic accumulation, with normal eating and drinking but frequent diarrhea, a floating pulse at the inch position, and a small, thin, deep, and tight pulse at the guan position, it is named visceral binding. If the tongue has a white and slippery coating, it is difficult to treat."
2. "Guide to Tongue Differentiation: Differentiation of Tongue Colors" quotes Ma Liangbo: "A thick and greasy tongue coating resembling accumulated powder is called a pink tongue coating. Traditional theories consider it a white coating, but in reality, powder and white represent cold and heat respectively, akin to the difference between water and fire. Warm diseases, Rebing, pestilence, seasonal epidemics, and external contraction of foul and improper qi, with internal accumulation of latent cold or heat, pathogenic heat spreading, and triple energizer fullness, often present with this tongue. Treatment should focus on cooling and draining heat. If the coating is powdery white and dry, it is urgent to use Rhubarb and Coptis Heart-Draining Decoction or even purgation with nitre and rhubarb. It is crucial to avoid adhering to old theories and mistaking it for a white coating, as this would be a grave error."