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Traditional Chinese medicine (TCM) theory posits that health is determined by a balanced flow of 3 substances: Qi, blood (Xue), and body fluids. Illness is identified via the 8-principle theory with the following 4 paired components: (1) hot and cold, (2) excess and deficiency, (3) interior and exterior, and (4) yin and yang. Using these 8 principles, the TCM practitioner identifies imbalances related to the patient’s Qi (vital energy), blood, or body fluids. 


TCM diagnosis is also based on 5 organ networks: the lungs/ colon, spleen/stomach, heart/small intestine, kidneys/bladder, and liver/gallbladder. These networks are then associated with 5 characteristics: element, cycle of development, season, climate, and emotion. Each organ network is capable of incurring TCM pathogenic factors arising from imbalances in the 1 or many of the 5 characteristics. Pathogenic factors include wind, heat, dampness, phlegm, dryness, and cold. When organ networks are in a state of imbalance, such as excess or deficiency in qi, blood, or fluids, the patient demonstrates a pattern of disharmony manifesting as symptoms.


Tongue evaluation dates from the Shang Dynasty (1600 BC to 1000 BC) and consists of visually inspecting the tongue body for vitality, color, shape, moisture, and movement and assessing the tongue coating for color, thickness, distribution, and characteristics at the root. According to TCM theory, the tongue provides a geographic map of organ systems; characteristics of the tongue in each of these areas provide information critical to the TCM diagnosis. TCM tongue diagnosis is considered a pillar of TCM diagnosis because it provides clearly visible clues to a patient’s pattern of disharmony. The tongue has many relationships and connections in the body, both to the meridians and the internal organs. It can present strong visual indicators of a person's overall harmony or disharmony. Since the tongue always reflects the basic, underlying pattern, it is extremely reliable, especially whenever there are conflicting manifestations.

Tongue Diagnosis

Observation of the tongue is based on four areas: the tongue body color, the body shape, the coating and the moisture. Of these four, the tongue body color is the most important (except in acute conditions, when coat is most important) and its diagnostic indications help clarify the pattern of disease, especially when there are conflicting signs and symptoms. Tongue movement can also be a useful indicator as can the sublingual veins seen on the underside of the tongue when it is curled up.


Each area of the tongue reflects the state of specific organs – the tip corresponds to the heart, the front to the lungs, the center to the spleen and stomach, the rear, first to the intestines, then going farther back to the bladder and uterus and then to the kidneys at the root, while the inside-sides correlates to the gall bladder and the edge-sides to the liver. Tongue color, shape, coating and moisture may vary in each of these areas and thus indicates the condition of imbalance or health in those corresponding organs. The following tongue indications are expressed in TCM terminology.

Channels/Meridians Reaching the Tongue

According to TCM, the tongue has a special relationship with the Heart, in that the Heart opens to the tongue. The tongue is said to be an "offshoot" of the Heart, or "flowers" into the Heart.

  • Heart Channel (Hand Shaoyin)
    - The Luo connecting channel connects to the root of the tongue.

  • Spleen Channel (Foot Taiyin)
    - An internal branch of the primary channel spreads over the lover surface of the tongue.
    - The tongue is penetrated by the Spleen Divergent channel.

  • Kidney Channel (Foot Shaoyin)
    - An internal branch of the primary channel terminates at the base of the tongue.

  • Bladder Channel (Foot Taiyang)
    - A branch of the muscle/sinew channel binds to the root of the tongue.

  • San Jiao Channel (Hand Shaoyang)
    - A branch of the San Jiao muscle channel links with the root of the tongue.

Tongue Body Color

The body color indicates the condition of blood, qi, yin, yang, fluids and the yin organs (heart, spleen, lungs, kidneys and liver). As well, it shows any long-term pathological disharmonies in chronic diseases and the constitutional weaknesses. It is a reliable indicator of the underlying patterns of disharmony. The normal tongue in TCM has a light red or pinkish body with a thin white coating. 


Bluish Purple or Reddish-Purple Tongue Body

  • Purple can indicate both Heat and Cold conditions.

  • A reddish-purple tongue indicates Heat and Blood Stagnation.

  • A dark reddish-purple tongue that is dry usually indicates depleted fluids due to Excess Heat.

  • A light purple, bluish purple, or greenish purple tongue body color can indicate Cold and Blood Stagnation.


Red Tongue Body

  • A red tongue body is darker than the normal red, which is pinkish in color. It indicates either Deficient or Excess Heat.

  • A red tongue body with a thick yellow coat or swollen buds indicates Excess Heat.

  • A red tongue body with a bright shiny coat, little coat, or no coating indicates Deficient Heat.


Red Tip

  • Heat in the Heart Zang.


Scarlet Tongue Body

  • A scarlet tongue that is also peeled or shiny indicates Yin Deficiency, usually of the Heart and/or Lung depending on the area of swelling.


Dark Red Tongue Body

  • The red is darker and more crimson in color. This tongue body can indicate internal injury such as trauma (De Da), invasion of external evil in the Ying (Nutritive) and Xue (blood) levels, or it can indicate Blood Stagnation.

  • If there are red spots with a thin coat, this usually indicates damage to the Ying or Xue level.

  • If the tongue body also has cracks and there is little or no tongue coat, this usually indicates Deficient Heat due to internal injury.


Pale Tongue Body

  • Indicates the quality of Blood, reflecting Blood and/or Qi Deficiency or Cold.

  • If the tongue body is also moist, tender, and swollen, this can indicate Yang Cold.

  • A pale thin tongue body usually indicates Qi and Blood Deficiency.


Green Tongue Body

  • A green tongue body usually indicates Excess Yin Cold or the presence of a strong Excess evil with weak Zheng Qi. The Yang is not properly moving Blood and Fluids and there is Stagnation in the body.

  • Internal Wind may also present with a green tongue body.

The body shape reflects the state of Blood and Ying (Nutritive) Qi and indicates Excess or Deficiency. Constitution can also affect the shape of the tongue body. It also reflects any persistent long-term pathologies, as these change the tongue shape.



  • A stiff or rigid tongue is difficult to move (protrude, retract, side to side). This may cause speech abnormalities such as slurring or mumbled speech. A stiff tongue is an indication of Excess, and often one of Internal Wind.

  • If a stiff tongue is accompanied by a bluish-purple tongue body, this usually indicates potential or impending Wind-Stroke.

  • If a stiff tongue is accompanied by a bright red tongue body, this usually indicates heat in the Heart and Pericardium disturbing the Shen (Spirit).

  • If a stiff tongue is accompanied by a thick sticky tongue coating, this usually indicates "Phlegm Misting the Heart".


The flaccid tongue is the opposite of the stiff tongue. It is weak and lacks strength. It usually indicates Deficiency. When heat has consumed and damaged body fluids, they cannot rise to nourish the tongue. This can indicate Yin Deficiency, Qi Deficiency and/or Blood Deficiency.

  • A flaccid tongue that is also pale usually indicates Qi and Blood Deficiency.

  • A flaccid tongue that is also dark red, dry, and has cracks usually indicates extreme heat injuring fluids.

  • A flaccid tongue body with a scarlet tongue body usually indicates Exhaustion of Yin.


  • This is a very large tongue body and can indicate both Excess and Deficiency.

  • A swollen tongue that is also pale can indicate Qi Deficiency.

  • A swollen tongue that is also bright red and painful can indicate Heart and Spleen Heat. This could also be due to excess alcohol consumption.

Big or Enlarged Tongue

  • An enlarged tongue can indicate Phlegm, Damp, or Water Stagnation.

  • An enlarged tongue with a pale body and a moist coat may indicate Spleen and Kidney Yang Deficiency.

  • An enlarged tongue with a red body and a greasy yellow coat may indicate Spleen and Stomach Damp-Heat.

Half the Tongue Is Swollen

  • A half-swollen tongue may indicate general weakness of the meridians.

Hammer Shaped

  • This is where the front half or third of the tongue is enlarged at the sides.

  • A hammer shaped tongue usually indicates Spleen, Stomach, and Kidney Deficiency.

  • This tongue is almost always indicative of a serious condition and may indicate mental illness.


Local Swelling on One Side

  • Localized swelling of tongue with a normal tongue body color indicates Qi Deficiency.

  • Localized swelling of tongue with a red tongue body color indicates Qi and/or Blood Stagnation

Swollen Sides

  • A tongue with swelling in Liver and Gallbladder area usually indicates Rising Liver Yang or Liver Fire.

Swollen Between the Tip and the Central Surface

  • This area corresponds to the Lung area and usually presents with a normal or pale tongue body.

  • This tongue is usually found in patients with chronic Lung and Spleen Deficiency, which tends toward Damp and Phlegm accumulation.

Swollen Edges

  • This tongue may indicate Spleen Qi or Yang Deficiency.

  • If Spleen Yang is Deficient, the edges will also be wet.

Swollen Tip

  • When the very tip of the tongue is swollen, it usually indicates Heart problems.

  • If the tongue is also deep red, this may indicate Heart Fire.

  • If the tongue is normal in color or pale, this may indicate Heart Qi Deficiency.

Short and Contracted

  • When the patient cannot show the entire tongue, it usually indicates a more severe disease.

  • If the tongue is also moist and pale, this indicates stagnation of Cold (bluish/purple) in the meridians or Spleen Yang Deficiency.

  • If a contracted tongue also has a sticky tongue coating, this may indicate Turbid-Phlegm blocking the channels.

  • If the tongue is also deep red and dry, excessive heat has consumed Body Fluids and stirred up Internal Wind.

  • A short, swollen, tender, and pale tongue usually indicates Qi and Blood Deficiency.

  • A short or small frenum may be inherited and is normal.



  • There is difficulty in retracting the tongue.

  • This indicates interior Excess Heat, Heart Fire, or Phlegm-Fire Misting the Heart.

  • There may be numbness which is associated with neurological imbalances or trauma.

Front Swollen

  • Swelling towards the front one-third of the tongue may indicate Phlegm retention in the Lungs.


  • This can indicate that Qi and Blood are deficient and not able to properly nourish and moisturize the tongue. The tongue body will also usually be pale in color with Qi and Blood Deficiency.

  • A thin tongue that is also dark red and dry may indicate Yin Deficient Fire.

Tongue Body Shape

Specific Tongue Body Features

Rough or Tender Texture

  • A tender tongue that appears smooth, delicate, and is possibly swollen indicates deficiency.

  • A rough tongue that appears wrinkled and rough indicates Excess.

Red Spots

  • Red spots may indicate Heat Toxins in the Blood or Heat Toxins attacking the Heart.

  • Red spots can indicate the presence of Damp-Heat in the Xue Level, where the internal organs are accumulating toxins.

  • Red spots on the Tip (Lung/Heart area) is usually not severe and may present in the beginning stages of illness.

  • Red spots on the entire tongue may indicate a more severe illness.

  • Red spots on the sides of the tongue (Liver/Gallbladder area) may also indicate a more severe illness.

  • Red spots on the back of the tongue (Kidney area) may indicate the advanced stage or chronic nature of an illness.


White Spots

  • White spots are usually due to Spleen and Stomach Qi Deficiency together with excess heat accumulating in the body. In this case, the tongue may also have sores and pus.

Black Spots

  • Black spots usually indicate Qi and Blood Stagnation or heat in the Blood.


Deviated Tongue Body

  • This is where the tongue tends toward one side of the mouth.

  • This is due to Wind, either from exterior Pathogenic Wind or Internal Wind-Damp patterns.


Moving, Lolling, Wagging Tongue Body

  • Generally, excess tongue movement indicates either the depletion of Qi, or the presence of Wind. This can indicate heat in the Heart and Spleen channels stirring up Internal Wind.

  • In children, this may indicate developmental problems.


Teeth Marks on Tongue Body (Scalloped)

  • If the tongue body has normal color, this usually indicates Spleen Qi Deficiency.

  • If there are teeth marks together with a swollen tongue, this may indicate Spleen Yang and/or Qi Deficiency.

  • If the tongue is also pale and moist, it is more likely Spleen Yang Deficiency or a Cold-Damp pattern.


Quivering or Trembling Tongue Body

  • Trembling of the tongue that cannot be controlled may be due to external febrile disease or excess heat consuming Yin. The excess heat stirs up Internal Wind. The tongue body will be a deep red color and the pulse will be rapid.

  • If the tongue body is pale and trembling, this usually indicates a chronic condition of Qi and Blood Deficiency, where the tongue is not being nourished.

  • Side effects of some western medications (pharmaceuticals) may cause trembling of the tongue.

Tongue moisture designates the state of dampness or dryness in the body, and thus reveals the state of Yin and Fluids in the body.

Dry Tongue Body

  • Deficiency of Yin and Fluids

Excess Wet Tongue Body

  • Excess dampness

Tongue Body Moisture

Tongue Coating

The tongue coating points to the condition of the yang organs (small intestine, stomach, large intestine, urinary bladder and gall bladder) and the location of the illness. 

White Tongue Coat

  • A thin white tongue coating is normal.

  • A thin white tongue coating can also indicate external Cold patterns when the appropriate clinical symptoms are present.

  • With a moist and pale tongue, a thicker white coating can indicate Damp-Cold.

  • A dry white coating can indicate Cold turning to Heat and starting to dry body fluids.

White Like Powder Tongue Coat

  • A white and thick tongue coating like powder indicates turbidity and external pathogenic heat. This coating will usually change to yellow after a short time if the patient is not treated.

  • If the tongue body is dark red, interior toxins may be present.

White Like Snow Tongue Coat

  • This may indicate exhaustion of Spleen Yang with Damp-Cold in the Middle Jiao.

Yellow Tongue Coat

  • A slightly yellow coating indicates Wind-Heat or Wind-Cold turning to Wind-Heat.

  • A yellow tongue coat indicates an interior heat pattern. The deeper the color of yellow, the more severe heat. A burnt yellow indicates further accumulation of heat in the body.

  • If the coating is yellow and moist and the tongue body is swollen and tender, this indicates interior Damp-Heat or Yang Deficiency. In the case of Yang Deficiency, the tongue is showing false heat signs, as the Yin has forced the Yang to the surface of the body.

Dirty Yellow Tongue Coat

  • This tongue coating may indicate Stomach and Intestinal Damp-Heat.

Simultaneous White and Yellow Tongue Coating

  • Can indicate a Shaoyang pattern.

  • Can indicate a simultaneous Heat and Cold pattern, or a Cold pattern turning to Heat.

  • Can indicate a simultaneous Interior and Exterior pattern.

Gray Tongue Coat

  • This tongue coating usually indicates an internal pattern of either Heat or Damp-Cold.

  • A dry gray coating can indicate internal Excess Heat scorching Body Fluids or Yin Deficient Fire.

  • A wet or moist gray coating usually indicates Cold-Damp Stagnation or Damp-Phlegm retention.

Black Tongue Coat

  • Like the Gray coating above, but more severe.

  • The black coating usually develops from gray or a burnt yellow coating.

  • A dry black coating (usually with cracks) may indicate excessive Heat burning body fluids.

  • A moist black coating and a pale tongue body may indicate Yang Deficiency, Internal Excess Cold, with or without the presence of Dampness.

  • Both Gray and Black tongue coating can indicate extreme Cold (wet tongue) or extreme Heat (dry tongue).

  • Western drugs such as antibiotics can also cause a black tongue coating.

Half Yellow, Half White (Longitudinally)

  • This coating may indicate Heat in the Liver and Gallbladder.


Yellow Root with a White Tip

  • This may indicate that exterior Pathogenic Heat is penetrating more deeply into the interior of the body.

Black in the Center, White and Slippery on the Sides

  • This may indicate Spleen Yang Deficiency with interior Damp-Cold

Thin Coating

  • Normal.

  • In disease, it indicates the disease is either external or an internal disease that is not severe.

  • If the tongue coating changes from thick to thin, this indicates pathogens are moving to the exterior of the body and the disease is waning.

Thick Coating

  • A thick coating usually indicates more of an internal disease that is more severe.

  • It may also indicate that exterior pathogenic factors have penetrated more deeply into the body.

  • A thick tongue coating may also indicate retention of food.

  • If the tongue coating changes from thin to thick, this indicates pathogens are penetrating deeper into the interior of the body.

Peeled, Mirrored, Shiny, No Coating

  • With a mirrored tongue, there is no coating on the tongue. In less severe cases, there may be a partial coating on the tongue.

  • If the body of the tongue is also red, it usually indicates that Stomach Qi and Yin is severely damaged.

  • If the tongue body is also light in color, this may indicate that Qi and Blood of the Spleen and Stomach is damaged and Deficient.

  • If the tongue body is also red or dark, Stomach and Kidney Yin is damaged (body fluids dried up) due to heat.

Tongue Coat Thickness

Tongue Body Cracks

Horizontal Cracks

  • Yin Deficiency

Transverse Cracks on the Sides of the Tongue

  • Spleen Qi and/or Yin Deficiency

Scalloped Tongue

  • Spleen Qi Deficiency Usually with Dampness

Crack in the Center

  • Stomach and/or Spleen Qi Deficiency

Crack Down the Center to Tip

  • Heart Pathology

Cracks Like Ice Floes

  • Yin Deficiency

Vertical Cracks in the Center

  • Spleen Qi Deficiency


Irregular Cracks

  • Stomach Yin Deficiency


Strange colors on the tongue usually reflect foods recently sucked or eaten. Have the person relax first before you look at it. The tongue should not be held out longer than twenty seconds at a time as the color changes quickly.

Tongue Diagnosis Techniques

The tongue is best observed in outdoor light and no sooner than ½-1 hour after eating. Sunlight will give the most accurate color of the tongue body and coat. If sunlight is not available, use a small flashlight - preferably a halogen light - to compare the tongue color to the original light source. 

The tongue should be extended in a relaxed manner and should not be held out for an extended duration.

Food and Drink
Food and drink, such as coffee, green tea, and candy may alter the color of the tongue coating.

Brushed Tongue
Some patients may brush their tongue to help freshen their breath or as an Ayurvedic practice. Ask the patient not to brush their tongue on the day of their TCM tongue diagnosis.

Seasons of the Year
In Summer, there may be more Dampness present in the tongue coating, leaving it slightly thicker and light yellow. In Fall or Autumn, the tongue may be thinner with a coating that is drier. In Winter, there may also be more moist or damp presenting in the tongue. In Spring, the tongue should be normal.

Time of Day
The coating of the tongue usually becomes thinner as the day progresses, while the color of the tongue body becomes redder and shinier.

Patient's Age
In the elderly, Qi and Blood Deficiency is more common, so the tongue may present with dryness and cracks. Infants tend to have a white thick coating that is easily removed; peeled tongues are also common. Overweight patients usually have more Damp and/or Phlegm and therefore their tongues may be larger and lighter in color.
Thin patients tend towards redder tongues.

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