Common Diagnostic Methods for Warm Diseases in TCM (Observation Diagnosis)

01 Observation of TeethTeeth Moisture and Dryness

Glossy and Dry: The surface of the teeth is dry but retains a shine—indicating Stomach Heat injuring fluids, with Kidney Yin not yet exhausted.

Dry as Bone: The surface of the teeth is dry and lacks luster—indicating Kidney Yin depletion.

Teeth Dry and Black: The teeth are dry without fluids, and their color is dark black—indicating pathogenic heat penetrating the lower jiao, injuring Liver and Kidney Yin, with signs of wind movement.

Bleeding Between Teeth

Bleeding between teeth with swollen and painful gums: Stomach Fire is agitated, indicating a solid pattern.

Bleeding between teeth without swollen and painful gums: Kidney Fire is rising, indicating a deficiency pattern.

Gum Nodules

★ Yin Blood: Gum bleeding with nodules on top, yellow like spoiled sauce, indicates Stomach Fire rising, with a deficiency pattern.

★ Yang Blood: Gum bleeding with nodules on top, purple like lacquer, indicates Stomach Fire agitation, with a solid pattern.

Dental Plaque

Teeth with plaque: Excessive heat injures fluids, and the qi and fluids have not yet declined.

Teeth without plaque: Kidney water is depleted, Stomach fluids are exhausted, indicating a severe condition.

Plaque like ash cake: Both Stomach and Kidney deficiency, fluids and qi are exhausted, with dampness and turbidity in action.

02 Observation of the Tongue

Location	Internal Injury and Miscellaneous Diseases	External Pathogenic Changes	Gastrointestinal Changes
Tip of the Tongue	Heart and Lung	Upper Jiao	Upper Abdomen
Middle of the Tongue	Spleen and Stomach	Middle Jiao	Middle Abdomen
Root of the Tongue	Kidney	Lower Jiao	Lower Abdomen
Side of the Tongue	Left Liver and Right Gallbladder

Significance of Tongue Diagnosis in Warm Diseases

① Distinguishing the type of pathogenic factor: Warm heat vs. damp heat.

② Analyzing the pathogenesis and symptoms: Stages of Wei, Qi, Ying, and Blood.

③ Judging the progression of the disease: Severity and prognosis, depth of pathogenic factors, strength of righteous qi, and the existence of fluids.

④ Guiding the formulation of treatment and medication.

Tongue Coating DiagnosisWhite Coating

① Thin white coating lacking moisture (slightly red on the sides and tip): Initial invasion of warm pathogens on the lung’s defensive qi, often seen in the early stages of wind-warm disease, indicating wind-heat exterior syndrome.

② Thin white dry coating (red on the sides and tip): Exterior warm disease not resolved, lung fluids already injured; constitutionally deficient in fluids and then exposed to wind-heat; dryness and heat initially invading the lung’s defense.

③ Thick white greasy coating: Damp heat clashing, turbid pathogens invading. Often seen in damp-warm diseases where dampness is heavier than heat, obstructing the qi aspect and leading to excessive dampness.

④ Thick white dry coating (red tongue): Spleen dampness not transformed, stomach fluids already injured; stomach dryness injuring qi, qi not transforming fluids.

⑤ Greasy white coating (red tongue): Dampness obstructing heat, obstructing qi aspect and leading to dampness and turbid pathogens obstructing the ying aspect.

⑥ White greasy coating thick as accumulated powder with a purple tongue (accumulated powder coating): Damp heat and turbid pathogens, obstructing the membrane; damp heat epidemic disease.

⑦ White dry coating (grayish white, thick, hard, rough, and stiff like alkali): Retained turbid stagnation in the stomach, often seen in damp-heat warm diseases.

⑧ White crystal coating (thick and hard, rough like sandpaper): Rapidly transforming heat into dryness in the stomach, coating has not yet turned yellow, but fluids have already been greatly injured.

⑨ White moldy coating (full tongue covered in white, or spreading to the cheeks and gums, resembling mold, or with ulcerated spots, or resembling rice grains attached, or resembling rotten residue, easily scraped off): Internal turbid stagnation, declining stomach qi.

Yellow Coating

① Thin yellow coating not dry: Pathogenic heat initially entering the qi aspect, internal heat not severe, fluids not severely injured.

② Thin yellow and dry coating: Heat in the qi aspect is intense, fluids have been injured.

③ Yellow and white mixed and dry: Pathogen entering the qi aspect, exterior pathogen not yet resolved (Wei qi is affected).

④ Yellow and white mixed and greasy: Damp heat nature of warm disease, Wei qi is affected or summer heat obstructing Shaoyang in the qi aspect.

⑤ Yellow dry coating (not very thick, yellow and dry lacking fluids, red tongue): Intense heat in the qi aspect injuring fluids.

⑥ Old yellow coating (deep yellow, dry and prickly, with cracks): Yangming organ excess, fluids greatly injured.

⑦ Yellow greasy coating: Damp heat lingering in the qi aspect.

⑧ Yellow turbid coating (yellow greasy): Damp heat combined with phlegm turbidity or stagnation.

Gray Coating

① Gray dry coating: Yangming organ excess, Yin fluids greatly injured.

② Gray greasy coating: Warm disease combined with damp phlegm obstructing internally.

③ Gray slippery coating: Late stage of warm disease with Yang deficiency leading to internal cold dampness, dampness injuring Yang qi and transforming into cold damp syndrome.

Black Coating

① Black and dry coating with thick center: Yangming organ excess, Yin fluids greatly injured.

Developed from old yellow coating, based on excess in the organ and fluid injury, if the downward response is lost, pathogenic heat penetrates the lower jiao, potentially injuring Kidney Yin, forming black and dry coating, indicating “earth dryness and water depletion.”.

② Black and dry coating (black tongue coating, dry and thin without prickles, or tongue body withered, dark and not fresh): Late stage of warm disease, Kidney Yin exhausted.

③ Black and scorched coating (thin black and scorched tongue coating, tongue body dark and not fresh, tongue body withered): Pathogenic heat deeply penetrating the lower jiao and exhausting Kidney Yin.

④ Black and moist tongue coating: Warm disease combined with phlegm dampness; previously existing phlegm, now exposed to warm pathogens.

⑤ Dry black coating, tongue body pale white without luster: Heat entering the ying and blood, burning blood vessels, qi and blood deficiency, qi following blood loss, hence the tongue is pale white without luster; pathogenic heat has not yet transformed the coating color, hence it remains black.

⑥ Black and slippery: Damp heat transforming into cold, excessive dampness with weak Yang.

Distinguishing Tongue QualityRed Tongue

① Red tip of the tongue: Heat entering the ying aspect, heart fire rising (early stage of red tongue).

② Red tongue with red spots or cracks: Extreme heat in the heart and ying.

③ Tongue body bright red and tender, dry to the touch: Initial retreat of ying heat, fluids not yet restored (deficiency pattern).

④ Pale red tongue body, dry and lacking luster: Deficiency of qi, blood, and fluids.

Crimson Tongue

① Pure crimson and bright (tongue color deeper and brighter, moist and not dry without coating): Heat entering the heart envelope.

② Crimson and dry: Ying heat injuring Yin (often indicating a solid pattern).

③ Crimson tongue with large red spots: Intense heart fire, heat toxin attacking the heart (solid pattern).

④ Crimson tongue with yellow and white coating: Qi and ying (blood) affected.

⑤ Crimson tongue with greasy coating: Heat entering the ying and blood, combined with phlegm turbidity.

⑥ Crimson tongue bright and mirror-like: Stomach Yin declining.

⑦ Crimson tongue not fresh, dry and withered: Kidney Yin exhausted.

Purple Tongue

① Lingonberry tongue (tongue color crimson purple, covered with prickles, resembling lingonberry): Blood aspect heat toxin intense (often seen in severe throat infections).

② Liver and kidney tongue (purple and dull, resembling pig liver): Kidney and Liver Yin depleted.

③ Purple and dark: Warm disease combined with blood stasis.

Distinguishing Tongue State

① Rigid tongue body: Insufficient qi and fluids, collaterals lacking nourishment, signs of wind and convulsions.

② Short and retracted tongue: Internal wind disturbance, phlegm dampness obstructing the root of the tongue, often seen in convulsions.

③ Tongue curled and contracted: Severe signs indicating deep invasion of pathogenic factors into the Jueyin.

④ Soft and flaccid tongue: Liver and Kidney Yin fluids nearly depleted.

⑤ Slanted and quivering tongue: Liver wind internal movement.

⑥ Enlarged tongue body: If accompanied by yellow greasy coating, indicates damp heat toxicity rising to the tongue; if the tongue body is swollen and its color is dark, indicates alcohol toxicity attacking the heart.

03 Distinguishing RashesCharacteristics of Rashes

Rash: Skin lesions that are large and flat, spread across the skin, have a noticeable shape, do not hurt when touched, do not fade when pressed, and do not peel after disappearing (hemorrhagic).

Spot: Skin lesions that are small and fragmented, resembling grains of corn, protruding above the skin, hurt when touched, fade when pressed, and often peel after disappearing (congestive).

Distribution of Rashes

Rash: Often begins on the chest and abdomen, then spreads to the limbs.

Spot: Can appear in various forms, such as measles, generally starting from the soft palate and oral cavity, then spreading to the area behind the ears, face, and back, and then to the chest, abdomen, and limbs, referred to as “mucosal rash” (also known as “Hua’s spots”).

Dan Sha: Often first seen on the neck, gradually spreading to the chest, back, abdomen, and limbs, can spread across the entire body within a day.

Causes of Rashes

Heat obstructing internally, invading the ying and blood. Lu Zixian: “Rash is Yangming heat toxin, spot is Taiyin wind-heat.”

Signs Before Rash Emergence

Before the rash appears, symptoms such as strong fever, restlessness, red tongue, cold hands and feet, dizziness, deafness, and hidden pulse may be observed;

Before the spots appear, symptoms such as fever, restlessness, flushed face, red eyes, chest tightness, and cough may be observed.

Diagnosis and Clinical Significance of Rashes

Distinguishing Content	Favorable	Unfavorable
Observing Color	Bright red and moist: Blood circulation is smooth, righteous qi is still abundant, and pathogenic heat has an opportunity to exit.	Pale red: Insufficient qi and blood unable to emerge; bright red like smoke: indicates intense blood heat; purple red like cockscomb: indicates severe heat toxin; dark purple: indicates extreme fire toxin, often dangerous; bright black: indicates excessive heat toxin but qi and blood are still abundant; dark black with faint red: indicates internal fire stagnation with active qi and blood; dark black and dull: indicates declining vital energy and stagnation of heat toxin.
Examining Shape	Loose and fresh color scattered on the skin: Indicates external release of pathogenic toxins, favorable prognosis.	Tight and rooted, penetrating from the skin (like an arrow piercing, like a needle penetrating): Indicates deep-seated heat toxin difficult to expel, unfavorable prognosis.
Noticing Density	Sparse and even: Indicates light heat toxin, favorable prognosis.	Dense and merging into patches: Indicates heavy heat toxin, unfavorable prognosis.
Overall Pulse Signs	Heat receding and spirit clear: Indicates favorable signs of external resolution and internal harmony.	Heat not diminishing or rising, or rash just appearing and then disappearing, with signs of confusion, cold limbs, and hidden pulse: Indicates ominous signs of righteous qi unable to overcome internal heat toxin.

“Favorable signs” indicate that the rash’s emergence suggests the pathogenic heat is being expelled externally.

“Unfavorable signs” indicate that the rash is too dense, suggesting heavy heat toxin and indicating a severe condition.

Treatment Principles for Spots and Rashes

Treatment principles for spots: Clear Stomach, drain heat, cool blood, and resolve spots. If spots are accompanied by rashes, focus on resolving spots while also addressing rashes; if there is internal constipation, spots and rashes may be obstructed and not emerge, thus should clear the lower jiao; if there is internal obstruction, then exterior qi should be unblocked to allow spots and rashes to emerge.

Treatment principles for rashes: Disperse lung, expel pathogens, cool ying, and resolve rashes.

Contraindications for treating spots and rashes: “For spots and rashes, using ascending methods may cause bleeding, or fainting, or coughing, or confusion; using obstructive tonics may cause confusion.” This sentence mainly points out that for spots and rashes, ascending and tonifying methods should not be used recklessly, and one should not use pungent warming dispersing methods or tonics recklessly; additionally, one should be cautious not to use bitter cold substances too early when spots and rashes first appear, for fear of internal invasion of pathogenic factors.

04 Distinguishing White BlistersCharacteristics and Distribution

White blisters appear as small vesicles on the skin, resembling grains of corn, pearl-like in color, protruding above the skin, generally containing white transparent fluid, thus appearing crystal clear. White blisters emerge in batches, generally distributed on the neck, chest, and abdomen, less commonly on the limbs, and even less on the head and face; during regression, small skin flakes may shed.

Causes

Damp-heat pathogenic factors lingering in the qi aspect, steaming and obstructing the skin; having exterior symptoms without exterior pathogens.

Due to the damp nature being sticky, it cannot all emerge at once; after sweating once, a batch of rashes emerges. Generally, before the rashes appear, symptoms such as chest tightness and discomfort due to damp-heat obstruction may be present; these symptoms will alleviate after the white blisters emerge.

Clinical Significance and Treatment Principles

Damp-heat is significant, and obstruction is difficult to resolve; righteous qi can expel the pathogenic factors outward, and damp-heat has a tendency to emerge outward.

White blisters are an important sign of damp-heat disease, aiding in distinguishing the nature of the disease and the state of fluids and qi.

Crystal blisters: Refers to blisters that emerge crystal clear and plump, with clear granules; often after the blisters emerge, the heat intensity decreases and the spirit becomes refreshed, indicating sufficient fluids and qi, with righteous energy overcoming the pathogenic factors, and the pathogenic factors emerging outward. Clear heat, expel dampness, and promote the flow of qi.

Withered blisters: Refers to blisters that emerge as empty shells without fluid, color dry like bone, and often accompanied by persistent fever, confusion, and other symptoms, indicating that both fluids and qi are exhausted, righteous energy cannot overcome the pathogenic factors, and the pathogenic factors are trapped internally. Nourish Yin and benefit qi as the main treatment, supplemented by clearing and draining damp-heat.

Wu Jutong: Pure pungent dispersing and pure bitter clearing are both to be avoided.

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