Tongue diagnosis is an important diagnostic tool in Chinese internal medicine which shows the depth and nature of an imbalance and is less affected by short-term influences such as nervousness. All the meridians and the viscera connect directly or indirectly with the tongue therefore its appearance monitors the improvement or decline of the patient’s condition.  The physician is concerned with determining heat, cold, Yin or Yang and Qi and blood patterns. The diagnosis is objective compared with the many variations of the pulse and finally it’s easy and will help in understanding one’s own health. There are fundamental categories for inspection and observation of the human tongue; they are colour, shape and size, fur/coating and moisture

Tongue Colour

Normal tongue colour is light red, indicating that a person's vital energy (Qi) is strong. It also reflects the health of the internal organs and blood circulation. Changes in the tongue colour usually reflect chronic illness.

·        Pale

o       General deficiency

o       Excess cold, especially if thick white coating.

o       Spleen deficiency, especially if thin white coating

o       Blood deficiency, especially if dull, pale face and lips

·        Red

o       Heart fire especially if tip is red

o       Liver fire with red to sides

o       Lung fire then yellow to anterior

o       Excess heat, especially if there is a thick yellow tongue coating.

o       Yin deficiency, especially if tongue body is coated and coating is thin, absent or peeled

·        Blue/Black

o       Internal cold is present

·        Yellow

o       Stomach fire when yellow in centre

·        Purple

o       Stagnant Qi

o       Stagnant blood if dark purple tongue body and/or red spots on the tongue

Tongue Shape

Normal tongue shape is not too thick or thin, and the tongue body is smooth with no cracks. Changes in the tongue shape usually reflect chronic illness involving blood, qi, or body fluids.

·        Swollen or puffy

o       Liver fire

o       Spleen Qi deficiency, especially if teeth marks on the sides

o       Internal damp heat

·        Thin

o       Blood deficiency

o       Fluid deficiency

·        Trembling

o       Spleen Qi deficiency

·        Elongated

o       Heart heat

·        Stiff or deviated tongue

o       Internal wind is present

·        Teeth marks

o       Spleen deficiency

·        Sides curled up

o       Liver Qi stagnation; if sides are swollen and red it may indicate liver fire

·        Cracks

o       Excess heat or yin deficiency

o       Heart imbalance, especially if there is a crack down the middle of the tongue to the tip

o       Shallow midline cracks

§         Stomach deficiency

o       Short horizontal cracks

§         Spleen deficiency

Tongue Coating

Normal tongue coating is thin and white. A pale yellow and slightly thicker coating at the back of the tongue may also be normal. The tongue coating often indicates the health of the spleen and stomach. It also provides a good indication of acute illness, such as colds and digestive problems.

·        Thick

o       Excess

·        Yellow, thick, glossy

o       Damp heat

·        Dry, yellow

o       Excess heat

o       Stomach fire

o       Chronic cold deficiency

·        Wet

o       Acute cold deficiency

o       The yang Qi is not transformed and transporting fluids harmoniously resulting in accumulating dampness

·        Sticky/slippery coating

o       Accumulation of phlegm or dampness

·        Peeled or absent

o       Deficient Yin

o       Heart yin deficiency if it’s on tip of the tongue

o       Kidney Yin deficiency if it’s all over the tongue or at the back of the tongue and the tongue body is red

·        Raised and Red Papillae

• Excess heat
• Heart fire

·        Presence of red spots

•      Heat congestion

GENERAL INDICATIONS

• Smooth Tongue
  • A coated tongue is normal, a smooth red tongue is not.  The loss of papillae gives the tongue a red slick appearance, often beginning at the edges.  It suggests a Deficiency of Vitamin B12, niacin or iron.

• Hairy Tongue
  • Hair on a Hairy tongue consists of elongated papillae on the dorsum of the tongue and is yellowish to brown to black.  It is clinically benign with the etiology presently unknown.
• Geographic Tongue
  • Scattered red areas on the dorsum of the tongue that are denuded of their papillae and are smooth.  These areas appear in contrast o the normal roughened and coated surface, which yields a map-like pattern, which changes with time.  The condition is benign and the etiology remains unknown.
• Fissured Tongue
  • Fissures appear in the tongue with increasing age and at time become numerous, yielding the name “scrotal tongue”.  The only known significance is that food debris may accumulate in the crevices and become irritation.
• Cranial 12 paralysis
  • Paralysis of the Hypoglossal nerve produces atrophy and fasciculation’s of the involved half of the tongue.  Deviation toward the paralyzed side occurs when the tongue is protruded.
• Varicose Veins
  • Small purplish or blue-black round swellings may appear under the tongue with age and are known as “caviar lesions.”  They are considered not clinically relevant and it is prudent to reassure the patient:      
• Leukoplakia
  • A thickened white patch adherent to the mucous membrane.  Its appearance looks like “dried white paint.” Leukoplakia may involve any part of the oral mucosa.  This is considered a possible signs of Pre-malignancy.
• Carcinoma
  • Any ulcer or nodule which fails to heal in two or three weeks must be considered suspicious.  Look for it at the base or edges of the tongue as Carcinoma is rare on the dorsum of the tongue.