Tongue Apperance and Mechanisms (A Quick Guide)

Tongue diagnosis is a powerful means by which a practitioner of Chinese medicine can quickly locate the solution to many issues of internal medicine.
What follows on this page are the various tongue body and coating appearances, how they came to look that way (mechanisms) and what they indicate.
Tasty!

Tongue Body Color
COLOR	INDICATIONS	MECHANISM
Pale	deficiency	Qi and/or Blood unable to fill tongue body
	deficiency of Qi	Qi too deficient to guide Blood to tongue to give it pink color.
	deficiency of Blood	Lack of Blood can’t give tongue pink color
	deficiency of Yang	Lack of Yang can’t lift Qi and Blood to tongue to give it pink color.
Pink	normal	Pink means adequate Qi and Blood.
Red	heat	Heat accelerates and expands movement of Blood which fills tongue with more red color.
	excess heat	Often found with a thicker tongue coating, likely yellow.
	deficiency heat	Often found with a thin or scanty tongue coating.
Crimson (dark red)	Ying or Blood level heat. Blood stagnation with heat	Heat damages yin, causes the red to become more concentrated and darker. Blood stagnation with heat Blood stagnation causes purple color, heat makes it more red.
Purple	Blood stagnation	The slower the Blood moves, the more depleted of oxygen it will become, giving rise to a tendency toward the blue color. Purple is a transitory color between pink and blue.
Blue-Purple	Blood stagnation with, or due to cold.	Cold (blue) impedes movement which causes Blood stagnation (purple)
Pale Purple (“dusky”)	Blood stagnation with or due to deficiency of Qi, Blood, or Yang	Blood stagnation is purple, pale is deficiency.
Blue	Internal cold	Cold impedes movement which allows red blood to lose its oxygen giving rise to the blue color. (western explaination)

Tongue Body Shape
SIZE	INDICATIONS	MECHANISM
Small tongue body	deficiency of Blood or Yin	Lack of fluids causes tongue to shrink in size.
Swollen tongue body (vertically enlarged)	excess heat or alcohol/drug toxicity	Heat pushes more Blood into tongue body to increase its size.
Flabby tongue body (horizontally enlarged)	damp or phlegm	fluids fill tongue and enlarge it horizontally.
Teeth marks	damp or phlegm	a continuation of the flabby tongue in which the teeth indentations are visible.

Tongue Body Cracks
CRACKS	INDICATIONS	MECHANISM
Cracks in tongue body	Blood or Yin deficiency	Fluids unable to moisten and nourish tongue body giving rise to cracks like dried earth.
+red	Yin deficiency	Fluids unable to moisten and nourish tongue body.
+pale	Blood deficiency	Fluids unable to moisten and nourish tongue body.
+teeth marks cracks on lateral sides, look like fish’s gills	dampness	Damp prevents fluids from rising up to tongue to nourish it.

Prickles, dots, spots
SPOTS	INDICATIONS	MECHANISM
Prickles, dots, spots	heat or stagnation
+red	heat	Heat causes too much Qi and Blood to rise to the tongue where it causes the body to develop dots, points, spots, etc.
+purple (brown, dark)	Blood stagnation	Blood stagnation always looks purple.

Tongue Bearing Issues
BEARING	INDICATIONS	MECHANISM
Stiff tongue	Spasm due to internal wind	Excess heat, or a deficiency of Liver Yin or Blood can cause wind causing the tongue body to become stiff.
Limp tongue	deficiency of Qi, Blood, or Yin.	Lack of nutrients cause the tongue to become limp.
Trembling tongue	Spasm due to internal wind	Excess heat, or a deficiency of Liver Yin or Blood can cause wind causing the tongue body to tremble. NOTE: all tongues move, this sign is EXCESSIVE movement.
Deviated tongue	Internal wind, phlegm in channels	Something is blocking the channels and collaterals on one side of the tongue preventing its movement. This is also a “check in with a neurologist” indication due to the possibility of a tumor impinging a cranial nerve.
Engorged Sublingual Veins	Qi and/or Blood stagnation	Blood flow is impeded, giving rise to the appearance of backed-up Blood beneath the tongue.

Coating Color
COLOR	INDICATIONS	MECHANISM
White	cold	White and clear things in TCM are dilute and cold.
Yellow	heat	Yellow things in TCM are more concentrated due to heat damaging the Yin.
Gray	interior cold or heat	heat or cold is damaging the interior.
Black	extreme interior cold or heat	a further exasperation of the gray coating

Coating thickness
THICKNESS	INDICATIONS	MECHANISM
Thin coating	exterior syndrome or normal	If you can see through the coating to the body of the tongue, it is thin.
Thick coating	excessive condition, interior, damp, phlegm, food stagnation	Coating is the “smoke” of the stomach. Pathological factors rise with the Stomach Qi to the tongue coating.

Coating Moistness
MOISTNESS	INDICATIONS	MECHANISM
Moist coating	normal	the coating is neither excessively wet, dripping, or dry
Glossy (excessively shiny or wet) coating	internal cold, Yang deficiency	Yang deficiency or cold that damages Yang impedes the transformation of fluids giving rise to the accumulation of dampness or phlegm which shows up on the tongue in the form of the excessively wet coating.
Dry coating	dryness, heat, Yin deficiency, Yang deficiency	Here, we have a variety of factors that damage the body fluids including heat and dryness. Yin deficiency is obviously a form of internal dryness, and Yang deficiency can give rise to dryness in the body if the Yang is too weak to transform dietary water into body fluids.

Coating Distribution
DISTRIBUTION	INDICATIONS	MECHANISM
Even coating	phlegm-damp accumulation in the middle Jiao	The tongue indicates the conditions throughout the entire body, but also focuses on the Spleen and Stomach in particular. One map that is laid atop the tongue suggests that the entire tongue indicates the condition of the Spleen and Stomach only. So, a coating that covers the entire tongue can sometimes indicate only a pathology of the middle Jiao.
Coating on the anterior third (front third)	superficial invasion of pathogenic factor	The anterior third of the tongue is related to the Lungs and Heart. When a pathogenic factor enters the body, it generally enters through the Lungs, and so this thick coating on the anterior third of the tongue indicates this superficial invasion.
Coating in the middle only.	Phlegm and/or damp in the middle Jiao	Middle of the tongue is related to the middle Jiao.
Coating on one side or the other.	Shao Yang disease	Most pathologies that are one-sided or have symptoms that flip-flop between opposites (i.e. alternating chills and fever) indicate that the pathological factor has found its way to the Shao Yang channel, level, or organ (GB).
Peeled/Scanty/Coatless	Stomach Yin or Kidney Yin deficiency	Because the tongue coating is the smoke of the Stomach, and this smoke requires some Yin to evaporate up toward the tongue, a lack of Yin will cause a lack of smoke to rise and a lack of coating.
Geographic coating	Stomach Yin or Stomach Qi deficiency	Coating is the smoke of the Stomach. The Yin is what is heated to cause the smoke, while the Qi is that heating activity. In the absence of either of these factors, the coating can appear missing on portions of the tongue.