Abnormal taste is a kind of information that indicates disease and should be brought to the attention of doctors and patients themselves. Bitterness in the mouth: clinical observation of bitterness in the mouth is mostly seen in liver and gallbladder heat evidence, intestinal and stomach heat evidence, etc.; in modern medicine, it is mostly a manifestation of acute inflammation, while liver and gallbladder diseases are the most common. This may be caused by bile excretion malfunction. Cancer patients may also feel bitterness on the tongue when eating sweet things because of the elevated sweet taste threshold and lowered bitter taste threshold. Pale mouth: Pale mouth is mostly seen in patients with prolonged illness and weakness of the spleen and stomach, and patients with loss of appetite after major surgery may also feel pale and tasteless in the mouth and tongue. The former is a manifestation of the lightness of the evil, while the latter is a sign of the weakness of the evil, whose meaning is obviously different from that of bitterness. Enteritis, dysentery and other digestive system diseases also often have a light mouth, the identification is mostly dampness in the gastrointestinal tract or host to cold evil, although the actual evidence, but we should pay attention to not use too bitter cold drugs. The clinical measurement, serious patients with light mouth, insensitive to sweet, sour, bitter, salty flavors, taste threshold appears generally elevated phenomenon. Sweetness of the mouth: patients with actual heat in the spleen and stomach, dampness and heat, and phlegm and fire in the liver and spleen can have a sweet sensation in the mouth and tongue, which the ancients called “spleen heat and sweetness in the mouth”. Research has proved that digestive system dysfunction can lead to abnormal secretion of various enzymes and increased amylase content in saliva, which stimulates the taste buds on the tongue and makes the mouth feel sweet. Diabetic patients with high blood sugar, saliva sugar also increased, so often feel sweet mouth and tongue. Astringency: When the bitterness threshold of the taste cells of the tongue is reduced and the tactile sensation of the tongue is abnormal, astringency can occur. Patients with liver and gallbladder stagnation and heat injury to yin or spleen and earth decay often have a dry or tasteless sensation in the mouth and tongue. In severe neurosis or after sleepless nights, salivary gland secretion is reduced, and the mouth and tongue may also feel dry and astringent. Various types of cancers have bitter taste and astringency in the late stage, which is considered by TCM as the failure of spleen and kidney and stagnation of qi and blood. Sour mouth: According to TCM, “sour mouth is caused by liver heat” and “sour mouth is caused by weak spleen and stomach qi and wood multiplied by earth”, so sour mouth is mostly caused by spleen deficiency and liver fire. Some people determine the saliva of patients with sour mouth, in which lactic acid, phosphatase, carbonic anhydrase content is higher than normal people, PH is on the acidic reaction. Salty mouth: salty mouth to the spleen deficiency wet, kidney deficiency fire for more. Because Chinese medicine believes that “salty for the kidney taste”, clinically common in the kidney yin deficiency, kidney fire on the floating neurosis, chronic pharyngitis acute attacks of patients. Sometimes the saliva of patients with salty mouth is measured, and the chloride content of sodium, potassium, calcium and magnesium is seen to increase, and the PH is on the weak alkaline reaction. Spicy mouth: spicy mouth is a combination of salty taste, heat and pain sensation. In Chinese medicine, it is mostly identified as kidney yin deficiency and liver fire, followed by lung deficiency and phlegm heat; it is sometimes seen in patients with hypertension, neurosis and menopausal syndrome. It is measured that when the room temperature is 18℃-22℃, the tongue temperature of normal people is mostly 33℃-35℃, and the tongue temperature of patients with spicy mouth is high, sometimes up to 36℃ or more. In addition, the tongue mucosa of patients with spicy mouth is more sensitive to salty taste and pain.