Tongue diagnosis, also known as observation diagnosis, is an important method for understanding the physiological functions and pathological changes of the body through observing the changes in the tongue’s appearance.
During tongue diagnosis, observations are made in the order of tip of the tongue – middle of the tongue – root of the tongue – sides of the tongue. First, observe the tongue body, then the tongue coating, for about 30 seconds. If the initial observation is unclear, allow the patient to rest for 3-5 minutes before re-examining.
The following is a compilation of commonly seen tongue coating patterns in TCM clinical practice, which we hope will be helpful:
Tongue Shape and Surface
1Red spots on the tongue – Excess internal heat
If there are red spots or prickles on the tongue, it indicates excessive internal heat.
Red spots and prickles on the tip, middle, and sides of the tongue represent excessive heart fire, excessive gastrointestinal heat, and excessive liver and gallbladder fire, respectively.
2Cracked tongue – Deficiency of essence and blood
Cracks on the tongue are generally uncovered by tongue coating, indicating deficiency of essence and blood.
A white tongue coating with cracks indicates deficiency of essence and blood; a crimson and dry tongue with cracks indicates excessive heat injuring body fluids.
3Teeth marks on the tongue – Yang deficiency
A pale tongue body with a pale coating indicates spleen and kidney Yang deficiency, with internal dampness and phlegm.
This tongue appearance is very soft, indicating Yang deficiency and a decline in physical strength.
4Pale white tongue – Internal deficiency of sweat
A pale and plump tongue indicates deficiency of Yang; a pale and thin tongue indicates deficiency of Qi and blood.
A pale tongue indicates a deficiency syndrome or cold syndrome.
5Red tongue – Presence of pathogenic heat
A red tip with prickles indicates heart fire; a tongue that is red with a yellow and dry coating indicates internal excess heat; a red tongue body with little or no coating indicates Yin deficiency with internal heat.
This indicates a heat syndrome, which may be due to excessive accumulation of heat in the body, while also observing if there are red spots on the tongue surface.
6Crimson tongue – Significant pathogenic heat
A crimson tongue with a dry body and prickles or cracks indicates intense internal heat; a crimson tongue without coating and smooth indicates exhaustion of stomach and kidney Yin.
This tongue appearance indicates that the pathogenic heat has deeply penetrated the blood and nutrients, usually resulting in depletion of body fluids, with deeper colors indicating more severe heat and symptoms.
7Purple tongue – Poor blood circulation
A bluish-purple tongue indicates poor blood circulation. A purple tongue with a reddish hue may indicate excessive internal heat accumulation.
Cold syndrome, heat syndrome, or blood stasis syndrome may present with this tongue appearance, primarily caused by poor blood flow.
Tongue Size
1Thick tongue – Internal cold deficiency
Pay attention to the color of the tongue, the coating, and whether there are red spots.
A yellow coating on the tongue often indicates excessive heart and spleen heat; a swollen tongue with a dark purple color often indicates blood stasis.
2Fat pale tongue – Weak Yang
Due to weak Yang, the warming and promoting functions are affected, leading to a weakened ability to distribute fluids, resulting in a swollen and pale tongue.
A fat pale tongue indicates weak Yang and retention of dampness.
3Thin red tongue – Nutritional deficiency
A reddish tongue indicates internal heat or inflammation, with prolonged heat damaging body fluids and depleting internal nutrition.
A thin tongue indicates a lack of nutrition and moisture in the body.
4Thin pale tongue – Deficiency of both Qi and blood
If there is a significant coating on the thin pale tongue, it is often accompanied by mild cold or digestive issues, indicating a weak constitution.
This primarily reflects a pathological state of deficiency of both Qi and blood, indicating malnutrition.
5Old tongue – Confrontation of righteous and evil
The tongue coating is yellowish-white or gray-black, indicating a predominance of excess syndrome and heat syndrome.
An old tongue is often seen in the stage of confrontation between righteous and evil, where the pathogenic Qi is strong, but the body’s resistance is also strong.
6Tender tongue – Low metabolic function
This often indicates deficiency syndrome, cold syndrome, or damp syndrome.
Individuals with weakened internal organ function, low nutritional metabolism, or weakened immune systems often present with this tongue appearance.
Thickness of Tongue Coating
1Thin coating – Mild condition
A thin white coating and a light red tongue are normal tongue appearances; a thin yellow coating primarily reflects the pathological characteristics of the initial stage of heat syndrome.
This indicates a normal tongue coating or an early stage of disease, or shows a mild condition.
2Thick coating – Gastrointestinal stagnation
If the tongue body is red, with a yellow, thick, and dry coating, it indicates excessive heat damaging Yin; if it is a light red tongue with a thick, white, greasy coating, it indicates phlegm, dampness, or food stagnation.
This indicates a transition from a mild to a severe condition, or the presence of gastrointestinal stagnation.
3Dry coating – Vomiting and diarrhea injuring fluids
If the tongue coating is merely dry and white, it indicates poor circulation of body fluids; if the tongue coating is dry and yellow, it indicates intense stomach heat damaging fluids; if the tongue coating is dry and black, it indicates extreme heat injuring Yin.
This generally indicates high fever, vomiting, and diarrhea injuring fluids. It is also important to check the color of the tongue itself.
4Rough coating – Fluid deficiency
If the dryness in the body becomes severe, it raises concerns about long-term chronic diseases, such as hyperlipidemia or diabetes, and individuals with asthma may experience difficulty breathing.
This rough coating indicates a severe deficiency of body fluids.
5Greasy coating – Dampness and turbidity accumulation
A white tongue coating that adheres to the surface of the tongue indicates internal cold and dampness; if the tongue coating is yellow, it indicates internal dampness or phlegm turbidity accumulating and transforming into heat.
This indicates dampness and turbidity accumulation, with Yang Qi being restrained, primarily indicating phlegm dampness and food accumulation.
6Putrid coating – Excessive internal heat
Be cautious of discomfort and infections caused by overeating.
Putrid coating is mostly associated with heat syndrome, primarily indicating food accumulation and phlegm dampness.
Color of Tongue Coating
1White coating – Dampness and phlegm accumulation
A thin white coating indicates a normal tongue coating or the initial stage of an exterior syndrome. A thin white and slippery coating indicates internal cold syndrome or dampness syndrome; a thin white and greasy coating indicates dampness and phlegm.
Based on the moisture level and thickness of the tongue coating, it can be classified into thin white coating, white slippery coating, white dry coating, and white powdery coating.
2Yellow coating – Transformation of cold into heat
A thin yellow coating indicates mild heat; a yellow coating indicates severe heat; a scorched yellow coating indicates extreme heat; a yellow greasy coating indicates damp-heat syndrome.
A yellow coating indicates a disease, primarily indicating spleen and stomach diseases, internal syndrome, and heat syndrome.
3Gray coating – Dampness and turbidity obstruction
Once the tongue coating turns gray, it indicates that the disease has taken root in the body, and the condition has become serious.
A gray-white tongue coating indicates internal cold dampness or dampness and turbidity obstruction; a gray-yellow and dry coating indicates internal heat, damaging body fluids.
4Black coating – Intensified pathogenic heat
A black dry coating indicates the influence of chronic diseases or inflammation; a black greasy coating indicates excessive accumulation of heat and dampness in the body.
A black coating indicates a more severe condition or a trend towards chronicity.
1. Typical Tongue Appearance of Qi Deficiency
1Pale fat tongue with stasis spots
Tongue quality: dull and swollen
Tongue coating: thin
Tongue surface: obvious stasis spots on the front half of the tongue
This tongue appearance is often seen in patients with fatigue, easy fatigue, cold intolerance, and abdominal distension due to weak transformation.
2Dull tongue, thin greasy coating
Tongue color: dark red
Tongue coating: thin greasy coating
Tongue surface: moist
This tongue appearance is often due to deficiency of righteous Qi and poor transformation in the middle burner. Patients may experience general fatigue, memory loss, poor appetite, and abnormal bowel movements.
3Fat tender tongue, mirror-like
Tongue color: slightly red
Tongue quality: tender
Tongue body: swollen
This tongue appearance is typical of both Qi and Yin deficiency, and such patients may experience fatigue, shortness of breath, mental fatigue, and poor digestion.
4Pale dark tongue with stasis spots
Tongue quality: dull
Tongue coating: few and thin white
Tongue body: red tip with slight stasis spots
This tongue appearance is called a dull tongue, and clinically, it is often due to complex conditions leading to long-term deficiency of both Qi and blood.
5Pale fat tongue with white coating
Tongue body: pale and large
Tongue quality: tender
Tongue coating: white
This tongue appearance is often caused by Qi deficiency, leading to lung and spleen Qi deficiency, resulting in a tender and swollen tongue with a white coating.
6Pale fat tongue with teeth marks
Tongue quality: pale
Tongue coating: white
Tongue body: swollen with teeth marks on the edges
This tongue appearance is often seen in sub-healthy individuals. Patients with this tongue appearance may experience indigestion, fatigue in the limbs, and unformed stools.
7Pale red tongue with stasis spots
Tongue quality: pale red
Tongue body: slightly swollen
Tongue tip: scattered stasis spots
This tongue appearance is often seen in chronic consumptive diseases, resulting from long-term deficiency of righteous Qi and Qi stagnation with blood stasis.
8Pale red tongue with thin white coating
Tongue quality: pale red
Tongue coating: thin and white
Tongue surface: moist
This tongue appearance is often due to weak spleen Qi, combined with weak middle Qi, leading to the inability of the spleen to control blood. Patients with this tongue appearance may easily experience fatigue and weakness.
9Pale red tongue with stasis spots
Tongue quality: pale red
Tongue body: slightly swollen
Tongue tip: scattered stasis spots
This tongue appearance is often seen in chronic consumptive diseases, resulting from long-term deficiency of righteous Qi and Qi stagnation with blood stasis.
10Pale red tongue with thin white coating
Tongue quality: pale red
Tongue coating: thin and white
Tongue surface: moist
This tongue appearance is often due to weak spleen Qi, combined with weak middle Qi, leading to the inability of the spleen to control blood. Patients with this tongue appearance may easily experience fatigue and weakness.
11Pale red tongue with stasis spots
Tongue quality: pale red
Tongue body: slightly swollen
Tongue tip: scattered stasis spots
This tongue appearance is often seen in chronic consumptive diseases, resulting from long-term deficiency of righteous Qi and Qi stagnation with blood stasis.
2. Typical Tongue Appearance of Yang Deficiency
1Fat tender tongue, pale white
Tongue quality: pale white
Tongue body: fat and tender
Tongue coating: white
This tongue appearance is often due to spleen and stomach cold deficiency, with insufficient Qi and blood.
2Pale fat tongue with teeth marks
Tongue color: pale
Tongue coating: white
Tongue body: fat with teeth marks on the edges
This tongue appearance is often seen in chronic disease patients, such as diabetes, hypertension, and hyperlipidemia.
3Pale tongue with white greasy coating
Tongue color: pale
Tongue coating: white greasy
Tongue body: fat
This tongue appearance is often due to cold dampness obstructing the meridians, leading to cold and dampness accumulation.
4Pale tongue with stasis spots
Tongue quality: pale
Tongue coating: white
Tongue body: fat with stasis spots
This tongue appearance is often seen in chronic disease patients, such as diabetes, hypertension, and hyperlipidemia.
5Pale tongue with white greasy coating
Tongue color: pale
Tongue coating: white greasy
Tongue body: fat
This tongue appearance is often due to cold dampness obstructing the meridians, leading to cold and dampness accumulation.
6Pale tongue with stasis spots
Tongue quality: pale
Tongue coating: white
Tongue body: fat with stasis spots
This tongue appearance is often seen in chronic disease patients, such as diabetes, hypertension, and hyperlipidemia.
7Pale tongue with stasis spots
Tongue quality: pale
Tongue coating: white
Tongue body: fat with stasis spots
This tongue appearance is often seen in chronic disease patients, such as diabetes, hypertension, and hyperlipidemia.
8Pale tongue with stasis spots
Tongue quality: pale
Tongue coating: white
Tongue body: fat with stasis spots
This tongue appearance is often seen in chronic disease patients, such as diabetes, hypertension, and hyperlipidemia.
9Pale tongue with stasis spots
Tongue quality: pale
Tongue coating: white
Tongue body: fat with stasis spots
This tongue appearance is often seen in chronic disease patients, such as diabetes, hypertension, and hyperlipidemia.
10Pale tongue with stasis spots
Tongue quality: pale
Tongue coating: white
Tongue body: fat with stasis spots
This tongue appearance is often seen in chronic disease patients, such as diabetes, hypertension, and hyperlipidemia.
11Pale tongue with stasis spots
Tongue quality: pale
Tongue coating: white
Tongue body: fat with stasis spots
This tongue appearance is often seen in chronic disease patients, such as diabetes, hypertension, and hyperlipidemia.
3. Typical Tongue Appearance of Yin Deficiency
1Cracked tongue with dry coating
Tongue quality: cracked
Tongue color: reddish
Tongue coating: yellow, slightly thick and dry
This tongue appearance is primarily seen in patients with phlegm disturbing the wind and damaging Yin fluids.
2Thin red tongue with thin white coating
Tongue quality: dark red
Tongue coating: thin white, slightly dry
Tongue body: teeth marks on the sides
A thin red tongue is often due to liver and kidney Yin deficiency, with internal stasis of toxins. Patients may experience dizziness, dry eyes, and easy fatigue.
3Red tongue with little coating
Tongue coating: little
Tongue quality: reddish
Tongue body: prominent papillae
This tongue appearance indicates liver and kidney insufficiency, leading to heat transformation and loss of nourishment. Patients may experience dry throat, insomnia, and vivid dreams.
4Cracked tongue with little coating
Tongue quality: tender, light color
Tongue body: swollen
Tongue surface: with cracks
This tongue appearance indicates Qi and blood deficiency, with liver and kidney Yin deficiency. If the tongue coating is thin white and slippery, it indicates accumulation of body fluids.
5Dark red tongue with thin yellow greasy coating
Tongue quality: dark red
Tongue body: swollen
Tongue coating: yellow thin greasy
This tongue appearance indicates patients may experience red cheeks, weight loss, night sweats, five palms heat, unstable sleep, dizziness, and dry stools.
6Bright red tongue with little coating
Tongue quality: bright red
Tongue coating: little
Tongue body: thin
This tongue appearance indicates kidney Yin deficiency, which cannot nourish the heart, leading to excessive heart fire, resulting in a red tongue with stasis spots.
7Cracked tongue with red tongue
Tongue quality: red
Tongue surface: with cracks
Tongue coating: little
This tongue appearance is often due to excessive Yin deficiency and prolonged heat damaging Yin, leading to depletion of body fluids and cracks on the tongue surface.
8Pale red tongue with mirror-like appearance
Tongue quality: dark red
Tongue coating: thin white, slightly dry
Tongue body: teeth marks on the sides
This tongue appearance is often seen in chronic consumptive diseases, clinically presenting as thirst, mental fatigue, fatigue, shortness of breath, and low voice.
9Cracked tongue with thin white coating
Tongue quality: pale
Tongue coating: thin white
Tongue body: slightly swollen
This tongue appearance indicates that the body has accumulated heat, lacking moisture or fluids. Patients with this tongue appearance may also experience dry mouth, mental fatigue, and other symptoms.
10Fat tongue with deep yellow greasy coating
Tongue body: fat with teeth marks
Tongue coating: deep yellow, thick greasy
Tongue surface: with cracks and stasis spots
This tongue appearance indicates that patients may experience fever, heavy body, headache, dry mouth, and constipation.
11Thin red tongue with yellow greasy coating
Tongue coating: yellow greasy
Tongue quality: dark red
Tongue body: normal
This tongue appearance is often due to internal heat and dampness accumulation, leading to symptoms such as fever, headache, and dry mouth.
4. Typical Tongue Appearance of Phlegm-Dampness
1Dark red tongue with yellow greasy coating
Tongue quality: dark red
Tongue coating: yellow, thick greasy
Tongue surface: slightly with stasis spots
This tongue appearance is often seen in patients with pain, stiffness, and numbness in certain areas of the body, dizziness, and memory loss.
2Dark red tongue with thin greasy coating
Tongue quality: slightly dark
Tongue quality: thin greasy, slightly yellow
Tongue color: dark red
This tongue appearance indicates patients may experience cold hands and feet, chest tightness, excessive phlegm, easy fatigue, joint pain, numbness of the skin, and gastrointestinal discomfort.
3Dark red tongue with yellow thick greasy coating
Tongue coating: yellow, thick greasy
Tongue body: swollen
Tongue quality: dark red
This tongue appearance indicates patients may experience chest tightness, excessive phlegm, abdominal fullness, easy fatigue, and a preference for rich foods.
4Cracked tongue with thin yellow greasy coating
Tongue quality: dark, slightly red
Tongue coating: yellow greasy, thin coating
Tongue surface: with cracks
This tongue appearance indicates patients may experience loose stools, heavy body, dry mouth, nausea, insomnia, and digestive issues.
5Dark red tongue with yellow thick greasy coating
Tongue coating: yellow greasy
Tongue quality: dark red
Tongue body: with teeth marks
This tongue appearance indicates that the patient may experience excessive heat and phlegm dampness accumulation.
6Teeth marks on the tongue with yellow thick greasy coating
Tongue coating: thick greasy, yellow
Tongue quality: dark red
Tongue body: with teeth marks
This tongue appearance indicates that the patient may experience emotional repression, difficulty in expression, or excessive thinking, along with symptoms such as heavy limbs and slow movements.
7Pale red tongue with thick white greasy coating
Tongue coating: white greasy, thick
Tongue color: pale red
Tongue body: swollen
This tongue appearance indicates that the patient may experience mental depression, chest tightness, rib fullness, and a sensation of obstruction in the throat.
8Dark red tongue with stasis spots
Tongue quality: dark red
Tongue coating: thin white
Tongue body: with stasis spots
This tongue appearance indicates that the patient may experience pain in the ribs, a dull complexion, fatigue, and abdominal fullness.
9Thin white coating with small tongue
Tongue body: small
Tongue coating: thin white
Tongue surface: slightly dry
This tongue appearance indicates that the patient may experience fatigue, a dull complexion, and other symptoms.
10Fat tongue with white greasy coating and stasis spots
Tongue quality: pale red
Tongue coating: white greasy
Tongue body: fat with stasis spots
This tongue appearance indicates that the patient may experience emotional depression, emotional fragility, and other symptoms.
11Dark red tongue with thin white coating and stasis spots
Tongue quality: dark red
Tongue coating: thin white
Tongue surface: with stasis spots
This tongue appearance indicates that the patient may experience fever, headache, fatigue, dry mouth, chest tightness, and other symptoms.