Red Tongue General Discussion
A red tongue indicates latent heat accumulating internally in the Heart and Stomach, reaching the exterior from the interior. Zhang Zhongjing stated: "If cold is injured in winter, it transforms into warm disease (Wen Bing) in spring, and into heat disease (Re Bing) in summer." Therefore, the tongue appears red and crimson. Additionally, in plague epidemics, where the illness is identical among both the elderly and young within a region, the tongue also presents as purely crimson with accumulated coating. If excessive food intake occurs, it aids heat to steam internally, causing the tongue to be red and the face crimson. In severe cases, both the face and eyes become crimson, and sores appear on the tongue. However, diseases vary in severity, and tongue manifestations range from mild to severe. They may appear at the root, tip, center, left, or right of the tongue; presenting with sores, erosion, swelling, rotting, thinning, shortening, or various other deformities. All these are caused by the accumulation and transformation of plague toxins and fire-heat. Treatments differ accordingly: those requiring resolution should have their toxins resolved internally; those requiring phlebotomy should have their blood removed via pricking. Regarding decoctions, there is nothing beyond Da Cheng Qi Tang (Major Order the Qi Decoction), Xiao Cheng Qi Tang (Minor Order the Qi Decoction), Huang Lian Jie Du Tang (Coptis Decoction for Resolving Toxicity), and San Huang Shi Gao Tang (Three Yellows and Gypsum Decoction). One can extrapolate from such categories.

Pure Red Tongue
The tongue appears purely red, indicating that the pathogenic heat of plague has just begun to accumulate internally. It is suitable to treat with Bai Du San (Poison-Resolving Powder) modified, or Sheng Ma Ge Gen Tang (Bupleurum and Kudzu Root Decoction).

Red Tongue with Pale Black Center
The tongue is red with a pale black center and slippery/moist texture. This is Taiyang Plague. If there is aversion to cold and exterior syndrome signs, use Shuang Jie San (Double Resolution Powder) combined with Jie Du Tang (Toxin-Resolving Decoction) to induce slight sweating. After sweating ceases, immediate purgation is required. If chest binding, irritability, and fixed gaze occur, it is incurable.

Red Tongue with Scorched Black Center
The tongue shows redness with a black shape resembling a small tongue in the center. This indicates plague toxin internal binding in the Stomach, where extreme fire manifests with water characteristics. Liang Ge San (Cooling the Diaphragm Powder) is suitable. If the black color is dry and hard, and makes a sound when scraped with a fingernail, urgently use Tiao Wei Cheng Qi Tang (Regulate the Stomach Order the Qi Decoction) for purgation.

Red Tongue with Black Spots
Small black spots appearing like stars on a red tongue indicate that plague heat enters Yangming through deficiency. Stomach heat causes macules. If red and crimson macules also appear on the body, Hei Shen Sheng Ma Tang (Black Ginseng and Bupleurum Decoction) or Hua Ban Tang (Macule-Transforming Decoction) are suitable.

Red Tongue with Black Tip
The tongue base is red while the tip is black. This indicates Foot Shaoin plague heat affecting Hand Shaoyin. Zhu Ye Shi Gao Tang (Bamboo Leaf and Gypsum Decoction) is indicated.

Red Tongue with Human-Character Fissures
The tongue is very red with fissures. This is due to Yangming heat-toxic steaming the upper diaphragm, manifesting as human-character patterns. Liang Ge San (Cooling the Diaphragm Powder) is suitable. If thirst is severe and flatus occurs, Da Cheng Qi Tang (Major Order the Qi Decoction) should be used for purgation.

Red Tongue with Broken Fissures
Minister Fire invades the Sovereign position (Heart), causing the tongue to be red, dry, fissured, and painful. Huang Lian Jie Du Tang (Coptis Decoction for Resolving Toxicity) added with Mai Men Dong (Ophiopogon Tuber) for its cold and moistening properties is suitable.

Red Tongue with Red Star Points
The tongue is pale red with large red star points resembling abscesses or scrofula. This indicates damp-heat injuring Spleen Earth, a sign of impending jaundice. Yin Chen Hao Tang (Artemisia Capillaris Decoction) or Wu Ling San (Five Ingredient Powder with Poria) may be selected.

Deep Red Tongue with Worm-like Erosion
The tongue is red with red points, pitted and rotten like worm-eaten flesh. This indicates failure of Water and Fire to interact and blazing heat-toxicity. Regardless of the number of days, Xiao Cheng Qi Tang (Minor Order the Qi Decoction) is suitable for purgation. If symptoms do not subside, follow up with Da Cheng Qi Tang (Major Order the Qi Decoction).

Red Tongue with Purple Sores
This tongue appearance is common in plague. Symptoms include no aversion to cold, immediate thirst, irritability, or coughing with phlegm. Jie Du Tang (Toxin-Resolving Decoction) added with Hei Shen (Black Ginseng) and Bo He (Mint), along with Yi Yuan San (Benefit Origin Powder), is suitable. If the Chi pulse (cun-guan-chi, specifically chi position) is absent, death is certain. Chills and tremors also indicate death.

Red Tongue with Slightly Yellow Root
Heat enters the Yangming Stomach fu-organ, hence the root of the tongue is slightly yellow. If there is sweat only on the head, cool body, and difficult urination, Yin Chen Hao Tang (Artemisia Capillaris Decoction) added with Zhi Zi (Gardenia Fruit) and Xiang Chi (Fermented Soybean) is indicated.

Red Tongue with Slightly Yellow Slippery Coating
After five to seven days of illness, a yellow coating in the center indicates Yangming syndrome. If the pulse is deep and solid with delirious speech, even if the coating is slippery, Da Chai Hu Tang (Major Bupleurum Decoction) is suitable. If dry, this indicates intense internal heat-toxicity; urgently use Da Cheng Qi Tang (Major Order the Qi Decoction) for purgation.

Red, Long, Swollen Tongue Protruding Outside Lips
The tongue is long, swollen, and protrudes beyond the lips. This indicates heat-toxicity attacking the Heart. Internally administer Xie Xin Tang (Drain the Epigastrium Decoction); externally use pricking to remove bad blood. Then apply Pian Nao (Borneol) and Ren Zhong Huang (Human Waste Charcoal) sprinkled on the tongue for cure.

Protruding Tongue (Nong She)
Frequent protrusion of the tongue out of the mouth is called Nong She. If it reaches above/below the nose tip or left/right of the mouth corners, it is an ominous sign. Jie Du Tang (Toxin-Resolving Decoction) added with Sheng Di Huang (Rehmannia Root) may be used. If effective, life is preserved; if ineffective, death ensues.

Flaccid Red Tongue
The tongue is flaccid and immobile, indicating injury to the Heart. Treatment should be based on pulse and syndrome analysis. However, fewer than one in ten patients survive.

Stiff Red Tongue
Stiffness at the tongue root with loss of voice, or inability to speak due to pathogen binding in the throat, is a death sign. If the pulse has spirit and external symptoms are mild, drugs for clearing Heart heat, descending fire, and dispelling wind-phlegm may be used; many will survive.

Red Tongue with Bleeding Tip
Bleeding from the tongue tip like splashing indicates excess Heat-Toxicity in the Heart. Xi Jiao Di Huang Tang (Rhinoceros Horn and Rehmannia Decoction) added with Da Huang (Rhubarb Root) and Huang Lian (Coptis Rhizome) is suitable.

Red Tongue with Double Gray Dry Center
In plague-heat disease, two gray lines on the tongue result from dietary indiscretion after illness recovery. This causes fever, delirium, and picking at clothes/empty air. If the pulse is slippery, one purgation brings relief. If the pulse is choppy and black stool is passed after purgation, death ensues.

Red Tip, White Root Tongue
The red tip is the natural color; white coating indicates exterior pathogen. With aversion to cold, fever, and headache, induce sweating. Without aversion to cold, but with fever, irritability, and thirst, this is a Taiyang interior syndrome. Use Wu Ling San (Five Ingredient Powder with Poria) to resolve both exterior and interior.

Trembling Red Tongue
Trembling of the tongue indicates instability and wriggling movement. This syndrome results from excessive sweating leading to Yang collapse, or wind leakage. Quan Xiang Da Bu Tang (Complete Great Tonifying Decoction) or Da Jian Zhong Tang (Great Construct the Middle Decoction) may be selected.

Thin, Withered, Long Red Tongue
The tongue color is dry red, thin, and long. This indicates the Qi of Shaoyin perishing internally and failing to ascend to the tongue. Even without other symptoms, if the pulse further declines and perishes, survival is unlikely within a day or night.

Short Red Tongue with White [Coating/Symptoms]
Mouth sores, short tongue, hoarseness, dry throat, and irritability result from forceful sweating in plague, or untreated cold transforming into this syndrome. Huang Lian Xi Jiao Tang (Coptis and Rhinoceros Horn Decoction) or San Huang Shi Gao Tang (Three Yellows and Gypsum Decoction) may be selected.

Red Edges Extending to Black Dry Tip
Plague disease treated improperly, or indulging in diet/medication non-compliance, leads to a dry black center of the tongue. Urgently purge once or twice, then again after slight relief, until balanced.

Red Tip with Purple Prickles
Appearance of purple prickles on the red tip after sweating and dietary relapse indicates critical urgency. Zhi Shi Zhi Zi Chi Tang (Immature Bitter Orange, Gardenia, and Fermented Soybean Decoction) added with Da Huang (Rhubarb Root) for purgation. Scrape off the prickles; if they do not regrow, safety is achieved. If they regrow, danger persists.

Red Tip with Black Root
On the second or third day of plague, the tongue root is gray-black. Urgently use Liang Ge San (Cooling the Diaphragm Powder) or Shuang Jie San (Double Resolution Powder) for mild purgation. By the fourth or fifth day, extreme fire mimics water, gradually turning deep black; purgation will no longer help. If pathogen binds in the throat, with closed eyes, absent pulse, and oily sweat, death occurs within one to two days.

Tender Red Tongue without Fluids
Excessive sweating and purgation deplete fluids. The tongue color is fresh red, tender like new tissue, appearing moist but actually dry and withered. Sheng Mai San (Generate the Pulse Powder) combined with Ren Shen San Bai Tang (Ginseng Three Whites Decoction) is used. However, it often proves ineffective.