Changes in tongue shape are not isolated phenomena; they are manifestations of changes due to fullness or emptiness, cold or heat occurring in the Zang Fu, in the Qi and Xue. By shape we understand the contours, consistency, texture and mobility of the tongue. Tongue shape can suggest the presence of certain pathogenic factors such as wind, dampness or phlegm.

Once the data regarding tongue color has been gathered, we must observe its shape before moving on to differentiate the coating or make a clinical diagnosis.

The shape of a normal tongue should be:

• Neither too swollen nor too thin.
• Flexible.
• Soft but not flaccid.
• The shape naturally narrows at the tip without becoming extremely thin like a "V".
• Without fissures or cracks.
• Comes out of the mouth easily.
• Has no involuntary movements but is also not rigid or immobile.

In general, tongue shape will indicate the state of excess or deficiency of the organism.

See: the 8 principles.

Swollen / Thin

Swollen tongue

A swollen tongue normally indicates accumulation of fluids. It is a condition of excess.

• Swollen, pale and moist: Dampness due to Qi or Spleen-Yang deficiency.
• Swollen and red: Indicates heat.
• Swollen and fresh red: Heat is in the Stomach and Heart, raising Qi and Xue.
• Swollen and deeper red: The redder it is, the closer it is to Heart Fire or Phlegm.
• Swollen, red-purple: Excessive alcohol consumption. Excess of external toxic Heat-Fire.
• Swollen, dull purple and greenish: With swollen lips of the same color. Blood stasis due to intoxication.
• Swollen with normal color: Dampness-heat-phlegm; It is a struggle between Dampness-heat of Spleen and Stomach with phlegm.

Thin tongue

A thin tongue indicates that fluids are lacking to nourish the tongue. It is a condition of emptiness.

• Thin and red: Heat or Fire due to Yin deficiency. Qi and Xue are lacking due to heat (fire consumes fluids and causes Yin deficiency or heat in Blood)
• Thin and pale: Deficiency of Qi and Xue

Teeth marks

A tongue with teeth marks on the sides indicates Spleen weakness.

Rigid / Soft

Rigid tongue

A rigid tongue indicates that the Shen is impaired (heat, delirium, difficulty speaking). Wind stroke (apoplexy, difficulty speaking).

• Rigid and swollen: Phlegm.
• Rigid and red: Heat that has penetrated into the Pericardium.
• Rigid and very red: Very high fever consuming the Body Fluids.
• Rigid and pale or pink: Apoplexy. Blood must be nourished and wind dispersed.

Soft tongue

"The tongue is muscle; if the muscle is soft, the tongue will be white" (Ling Shu).

• Soft and pale: Deficiency of Qi and Xue of Spleen Blood, Spleen Qi and/or Heart Blood or Heart Qi.
• Soft and very red: Fire or very high fever consuming Body Fluids or excess fire due to Yin Deficiency.
• Soft tongue without nasolabial groove: In elderly patients, if the nasolabial groove has also disappeared and appetite is lost: Deficiency of Earth (SP/ST)

Short / Long

Short tongue

• Short and swollen: Dampness.
• Short and pale: Stagnation of accumulated cold inside that contracts the sinews (deep, in the Jue Yin layer).
• Short and pink: Deficiency of Qi and Xue
• Short and red: Dryness and heat producing wind (consumes body fluids and shortens the tongue).

Long tongue

A long tongue normally indicates heat in the Heart.

• Long, hard and dry: Excessive internal heat.
• Long, swollen and intense color: Heat and phlegm disturbing the Heart.
• Long and numb: Qi deficiency.
• Extended: When protruded, it is difficult to retract. Also with excessive saliva. Indicates excessive internal heat.

Square tongue tip

• Severe asthenia.
• Heart problems (Shen or the organ)

Deviated tongue

• Deviated tongue: Wind attack in the collaterals (external or internal).

Trembling tongue

• Trembling and pale: Yang exhaustion, impairing the Body Fluids which are nearly depleted.
• Trembling and pink: Deficiency of Blood and Qi.
• Trembling and very red without saliva: Deficiency of Body Fluids with wind movement.
• Trembling and very red: Excess of heat generating wind.
• Continuous movement accompanied by agitation and flushing: Excess Heart Fire causing wind.
• Continuous movement accompanied by yellow coating and dry stools: Dryness and heat in the Spleen channel.

Sensation of numbness

The sensation of numbness in the tongue can indicate the following:

• Without apparent cause: Xue deficiency.
• Accompanied by dizziness or vertigo: Internal movement of Liver Internal Wind.
• Numbness at the corners of the mouth and face: Damage by wind and phlegm.

• Tingling: Sensation of numbness. Indicates that Blood and nutritive Qi are not reaching the tongue. Lack of Blood or circulation.
• Rigid tongue with tingling: Wind.

Geographic or map tongue

Geographic tongue is one in which certain areas have more or fewer taste buds. It indicates Earth problems, possible food intolerances and allergies.

Spotted tongue

With small dots of any color: red, white or black.

• Heat in Blood, toxic. (usually accompanied by a red tongue).
• Stagnation of Qi and Xue

Prickly tongue

In some areas it presents hypertrophied papillae. Indicates heat.

Blood on the tongue

• Without apparent cause: Heat in the Heart.
• Dry and yellow tongue with blood: Heat in the Stomach.
• Blood under the tongue: Heat in the Liver.

Tongue fissures

• Transverse fissures: Deficiency of original Yin.
• Fissures in the shape of "snowflakes": Yin deficiency in elderly patients.
• Pale tongue with fissures like "fine hairs": Spleen deficiency (the deeper the fissure, the greater the deficiency). Dampness.
• Fissures in the shape of "|" and "X": Dryness in the Stomach, exhaustion of Body Fluids and excess of internal fire.
• Red tongue with short vertical and transverse fissures: The tongue cracks due to heat. Yin deficiency and exhaustion of Body Fluids.