How to diagnose diseases by looking at the tongue

When it comes to illness, many people want to prepare for it. In fact, as long as you learn to look at your tongue in life, you can roughly identify the health status of your body and even diagnose some diseases. We must learn to judge the pathological changes of different organs by observing changes in different parts of the tongue. Traditional Chinese medicine often refers to tongue coating as the "gastroscope of traditional Chinese medicine". So let’s learn how to diagnose diseases based on tongue coating!

Tongue color and tongue coating in tongue diagnosis

Tongue color refers to the color of the tongue. The normal tongue color is light red. There are several common tongue colors:

(1) Pale white

It indicates that the patient suffers from deficiency syndrome, cold syndrome, and blood and qi deficiency syndrome. If the tongue is pale and thin, it means that both blood and Qi are deficient; if the tongue is pale and moist, plump and tender, with tooth marks, it is mostly a symptom of deficiency and cold. If the tongue is pale white, bloodless, withered and dull, and has no tongue coating, it is called a cooked white tongue. This condition is a critical illness and the patient's Yang Qi is weak and Yin essence is exhausted.

(2) Red tongue

The tongue is slightly redder than normal, and sometimes bright red. It means that the patient suffers from fever. If the tongue is bright red but dry and has little fluid, and the tongue coating is thick yellow, it is a syndrome of excess heat. If only the tip of the tongue turns red, it means that the heart fire is inflamed. Red edges of the tongue indicate excessive liver and gallbladder fire. If the center of the tongue is red, it indicates excessive heat in the middle burner. If the tongue is covered with dark red spots, it means that warm and hot evil has damaged the heart and spleen. Purple spots in the tongue indicate that a breakout is about to occur. A bright red tongue with little coating or cracks on the tongue indicates a syndrome of deficiency-heat. The tongue is red and tender, looks moist, and feels dry to the touch, which is a sign of fluid depletion.

(3) Red tongue

The tongue coating is dark red, with the color between red and purple, and is called a crimson tongue. It indicates that the patient has symptoms of external infection or internal injury. The formation of a red tongue is due to the excessive heat which accelerates blood circulation and causes fullness of the tongue's veins. The tongue is red and dry, with thorns and cracks on the surface, indicating severe internal heat that has entered the blood. If the tongue is red with yellow and white coating, it means that the evil is retained in the Qi. A crimson tongue with large red spots indicates heat toxins attacking the heart. A red tip of the tongue indicates a burning heart fire. A dry and red tongue indicates stomach fire damaging body fluids. A red root of the tongue indicates blood heat and internal dryness. If the tongue is red with little saliva and coating, and is thin or cracked, it is a sign of yin deficiency and hyperactivity of fire. If the tongue is red and withered, smooth and without coating, it is called a mirror tongue. This is a dangerous sign of depletion of stomach and kidney yin fluid. If the tongue is red with little coating and is moist, it is usually a sign of blood stasis.

(4) Purple tongue

It indicates cold, heat and blood stasis. If the entire tongue is purple, it means that the internal organs are extremely hot. The tongue is purple and swollen with large red spots, indicating that heat toxins are attacking the heart. The tongue is dark purple, which indicates blood stasis. Purple spots on the tip of the tongue indicate blood stasis in the heart and liver. The tongue is purple like pig liver, dull and dry, which is a dangerous sign of exhaustion of stomach and kidney yin fluid.

Tongue diagnosis

The history of tongue diagnosis in traditional Chinese medicine can be traced back to the Western Zhou Dynasty more than 3,000 years ago. It had already existed as a diagnostic method in traditional Chinese medicine during the Spring and Autumn Period, the Warring States Period, and the Qin and Han Dynasties. The existing classic Chinese medicine work "Huangdi Neijing" at that time involved knowledge related to tongue diagnosis, including tongue quality, tongue coating, tongue sensation and other aspects.

Tongue diagnosis mainly includes two parts: tongue quality and tongue coating. Tongue quality reflects the strength and weakness of the five internal organs' essence and qi, while tongue coating reflects the nature of pathogenic factors and the depth of the disease.