Tongue diagnosis is a crucial aspect of TCM observation, serving as a simple and effective method to assist in diagnosis and differentiation by observing the color and shape changes of the tongue.

The tongue is the sprout of the heart and the external manifestation of the spleen; the coating is produced by the stomach qi. Tongue diagnosis primarily examines the quality and coating of the tongue, including its shape, color, moisture, and dryness, to determine the nature of diseases, the severity of conditions, the abundance or deficiency of qi and blood, the balance of body fluids, and the status of the organs.

The tongue body, also known as the tongue quality, is the muscular and vascular tissue of the tongue.

The tongue coating is a layer of moss-like substance attached to the tongue body, produced by the stomach qi.

Three Major Tongue Qualities Indicating Possible Health Issues:

1. Cracked Tongue

The tongue surface shows varying degrees of cracks in different depths and shapes, which is known as a cracked tongue.

(1) Excess heat injures yin, often presenting as a red tongue with cracks; if you notice this phenomenon, seek medical attention promptly and avoid consuming heat-inducing foods. Instead, eat foods that nourish yin and reduce fire.

(2) Blood deficiency leads to dryness, often presenting as a pale white tongue with cracks; this tongue quality is common in patients with anemia or those recovering from major illnesses or surgeries. It is important to consume blood-nourishing foods gradually.

(3) Spleen deficiency with dampness, often presenting as a pale, plump tongue with teeth marks and cracks. This is common in patients with spleen deficiency and excess dampness; it is advisable to consume foods like yam and coix seed to strengthen the spleen and eliminate dampness.

2. Teeth-marked Tongue

The edges of the tongue show impressions from the teeth, which is known as a teeth-marked tongue.

(1) A pale white and moist tongue with teeth marks indicates internal cold and dampness. Patients should pay attention to warmth, avoid raw and cold foods, and minimize exposure to overly humid environments.

(2) A pale red tongue with teeth marks indicates spleen deficiency or qi deficiency. In daily life, one can consume Dang Shen (Codonopsis) and Fu Ling (Poria) in water.

(3) A red and swollen tongue with teeth marks indicates damp-heat phlegm obstruction. This condition is more severe, and it is recommended to seek medical attention promptly.

3. Enlarged Tongue

An enlarged, swollen tongue, or one with teeth marks, is known as an enlarged tongue.

(1) A plump and tender tongue, pale in color, with teeth marks, thin white coating, pale face, fatigue, reduced appetite, abdominal fullness, and loose stools, with a weak pulse. This is often due to spleen deficiency. It is advisable to consume foods that strengthen the spleen, such as yam, Poria, and coix seed.

(2) A large, plump tongue, pale in color, with teeth marks, significant swelling below the waist, reduced urination, cold limbs, a dull or pale complexion, and a weak or slow pulse. This is often due to kidney deficiency with water retention. It is advisable to consume foods like black beans and winter melon.

These Tongue Coatings Require Attention:

1. White Rough Coating and Dry Cracked White Coating

A white tongue coating can be thin or thick, with rough and loose granules, dry and hard, resembling sand or stones. When touched, it feels rough, known as white rough coating. If the granules are finer and the texture is hard with cracks, it is referred to as dry cracked white coating. Clinically, this is often seen in external heat illnesses and acute infectious diseases.

2. Yellow Greasy Coating

A yellow and greasy tongue coating, with tightly packed granules, is known as yellow greasy coating.

Yellow greasy coating indicates conditions of damp-heat stagnation, phlegm-heat transformation, or food stagnation transforming into heat; it also indicates external heat illnesses such as summer heat and dampness.

3. Gray Coating

A gray coating with a hint of black is referred to as gray-black coating.

Gray coating is dry and indicates excess in the Yangming organ, with damage to the yin fluids.

4. Black Coating

A darker coating than gray coating, often developed from gray or burnt yellow coating.

Black coating indicates internal heat extremes and excess cold, commonly seen in severe stages of illness.

5. Burnt Yellow Coating

A burnt yellow coating that is thick and deep yellow, especially prominent in the center or root of the tongue.

Burnt yellow coating indicates the presence of internal heat and stagnation in the stomach.

6. Geographic Tongue

A chronic marginal exfoliative glossitis occurring in the superficial layer of the tongue mucosa.

Geographic tongue is often associated with intestinal parasites, gastrointestinal dysfunction, or developmental issues in children’s nervous systems, as well as emotional fluctuations. It is commonly seen in children, especially in weak infants. Some patients may have congenital geographic tongue.

Parents of children with geographic tongue should pay attention to:

1. Ensure the child gets adequate rest and timely introduction of supplementary foods. Prevent picky eating to avoid gastrointestinal dysfunction and malnutrition. A mixture of almond, coix seed, and Poria can be made for the child, which can awaken the spleen and eliminate dampness while enhancing the child’s digestive function.

2. Carefully check for infections in the teeth, tonsils, and buccal mucosa, and treat promptly if found.

3. Maintain oral hygiene; gently brush the tongue from back to front with a soft brush 1-2 times each morning to remove exfoliated epithelium, which can yield significant results.

Every morning while brushing teeth, take 30 seconds to observe the tongue quality and coating; if there are significant abnormalities, timely adjustments are necessary!

TCM Preventive Health:8 Types of Tongue Coatings

The tongue is the most sensitive organ in the human body, and the tongue mucosa is the most active site for cellular oxidative metabolism. Therefore, diseases of various systems can be most sensitively reflected on the tongue, leading to the saying, “Changes in the tongue often accompany systemic disorders.” Among these, changes in tongue quality most reflect diseases, and tongue color reflects the inherent color of the organs. The changes in tongue color are related to the circulation of qi and blood, as well as the balance of fluids. Modern medicine believes this is related to blood flow velocity, blood viscosity, vascular contraction and relaxation, and blood volume.

The spleen opens to the mouth, and “the tongue is the external manifestation of the spleen and stomach”; “the coating is the result of the steaming of stomach qi”. Therefore, the tongue coating reflects the pathology of the spleen and stomach most promptly. In modern medicine, the thickness or exfoliation of the tongue coating depends on the condition of the tongue papillae. Atrophy of the tongue papillae leads to exfoliation of the tongue coating, while excessive differentiation of keratinized epithelial cells leads to thickening of the tongue coating. Different constitutions can also affect the tongue.

1.Normal Tongue

A healthy tongue is “pale red with thin white coating”. It is spirited and flexible. When extending the tongue, there is a slight gap between the tongue and the corners of the mouth; even if the mouth is open for several minutes, the tongue does not easily dry out. The sublingual veins appear pale purple, indicating smooth blood circulation and good health.

2.Blood Deficiency

Qi and blood are weak; the overall tongue is pale white with no blood color; the tongue coating is thin; the sublingual vessels are not distinct.

3.Yin Deficiency

The tongue quality is bright red or a crimson tongue; it has little or no coating or is shiny; there is little moisture or cracks.

Note: Cracks in the tongue do not necessarily indicate yin deficiency.

4.Yang Deficiency

The tongue body is plump, pale white, or has teeth marks.

5.Blood Stasis

Black spots or purplish spots on the edges and tip of the tongue, the entire tongue quality appears dark, purple, or bluish; sublingual veins are varicose.

Note: The liver governs the smooth flow of qi and stores blood, regulating emotions. Emotional distress or invasion by external pathogens can lead to prolonged liver qi stagnation, resulting in depression or irritability, chest and rib distension, and pain; qi leads blood, and prolonged liver stagnation can cause blood stasis.

6.Qi Deficiency with Blood Stasis

A pale white tongue or dark tongue quality, with thin white coating; black spots or purplish spots may be seen on the edges and tip; or sublingual veins may be engorged.

7.Phlegm-Dampness

Thick and greasy coating, slippery texture, or a sensation of phlegm obstructing the throat, often accompanied by an enlarged tongue or teeth-marked tongue.

Note: Phlegm-dampness constitution often arises from various external or internal factors leading to dysfunction of the organs’ qi transformation, resulting in stagnation of water and dampness, which in turn affects organ function.

8.Spleen Deficiency with Excess Dampness

The tongue is enlarged, with teeth marks, and the coating is thick and greasy, or there may be slight yellow phlegm at the root of the tongue.

Note: Teeth-marked tongue often results from pressure on the tongue body due to enlargement, thus teeth-marked tongue is often seen with an enlarged tongue, commonly indicating spleen deficiency and is a sign of deficiency syndrome. If the tongue quality is moist and the coating is white, it indicates spleen deficiency with cold dampness. If accompanied by yellow greasy coating, it often indicates damp-heat phlegm obstruction.

Reminder

In TCM, there is a saying, “Preventive treatment of disease”; do not wait until you are ill to see a doctor. Pay attention to self-diagnosis and maintenance when you are healthy. Experts suggest we learn to observe ourselves twice daily. The first observation is to check your tongue coating every morning. A normal tongue coating is: pale red color, thin white and even coating, and moderate moisture, which is essentially a pale red tongue with thin white coating. The second observation is to check the stool; normal stool is banana-shaped, while dryness and diarrhea indicate an imbalance in the digestive system.

— — The above knowledge is for the dissemination of TCM knowledge only and is not for treatment purposes. If you belong to a certain constitution, you will inevitably have corresponding symptoms, but it does not mean that having these symptoms categorically classifies you into that constitution; other diagnostic methods should also be considered.