Xiao Chai Hu Tang

Xiao Chai Hu Tang

From “Shang Han Lun”

[Composition] 12 grams of chai hu (half a jin); 9 grams of Huang Qin (three liang); 9 grams of Ren Shen (three liang); 9 grams of Ban Xia (half a sheng); 6 grams of Zhi Gan Cao (three liang); 9 grams of Sheng Jiang (three liang); 12 jujubes

[Administration] Decocted in water and taken orally.

[Indications] Shaoyang syndromes (both exterior and interior).

[Suitable Symptoms] Bitter taste in the mouth, dry throat, dizziness, alternating chills and fever, chest and flank fullness, irritability and nausea, a feeling of wanting to eat but unable to, a tense pulse, and a thin white tongue coating.

[Functions] Harmonize Shaoyang.

[Formula Explanation] The Shaoyang meridian runs along the ribs and flanks, situated between the Sun and Yangming meridians—this is precisely the area where the exterior and interior meet. When the pathogen and righteous qi clash, chills and fever alternate; when the pathogen resides in the ribs and flanks, chest and flank fullness appear; when qi is stagnant in the chest, irritability arises; when the liver’s wood overcomes the earth, nausea and loss of appetite occur; bitter taste in the mouth, dry throat, and dizziness are all signs of pathogen invasion in the Shaoyang meridian. In this formula, chai hu dispels the pathogen from the Shaoyang meridian, Huang Qin clears the heat from the Shaoyang meridian; together, these two herbs fulfill the major role of harmonizing Shaoyang and serve as the primary treatment. When the pathogen invades Shaoyang, qi inevitably becomes deficient, so Ren Shen and jujubes are used to replenish qi and restore vitality as auxiliary treatments. Shaoyang is also the liver and gallbladder; when the liver’s wood overcomes the earth, and stomach qi rises upward, vomiting occurs—so Ban Xia and Sheng Jiang are used to descend the rising qi and relieve vomiting as complementary treatments. Gan Cao harmonizes all the herbs and acts as a guide for harmony.

[Clinical Additions and Subtractions]

① “If the chest feels irritable without vomiting, remove Ban Xia and Ren Shen, and add one gourd fruit; if thirst occurs, remove Ban Xia and add Ren Shen, combining it with the previous amount to make four liang and a half, and gourd root four liang; if there is abdominal pain, remove Huang Qin and add three liang of shaoyao; if there is fullness and distension in the flank, remove jujubes and add four liang of oyster shell; if there is palpitations and difficulty urinating, remove Huang Qin and add four liang of茯苓; if there is no thirst but a slight fever, remove Ren Shen and add three liang of gui zhi, warming the body until a slight sweat appears, and recovery occurs; if there is cough, remove Ren Shen, jujubes, and Sheng Jiang, and add half a sheng of wu wei zi and two liang of dried ginger.” (from “Shang Han Lun”)

② Add Gui Zhi Tang to the above formula, known as Chai Hu Gui Zhi Tang (from “Shang Han Lun”), which treats cases of deficiency in both the exterior and interior.

③ Adding wine-fried Chang Shan and grass fruit can help suppress malaria.

[Reference Materials]

① “After five or six days of Shang Han, with a common cold, alternating chills and fever, chest and flank fullness, a feeling of wanting to eat but unable to, irritability and nausea, or chest discomfort without vomiting, or thirst, or abdominal pain, or flank fullness, or palpitations and difficulty urinating, or no thirst but a slight fever, or cough—Xiao Chai Hu Tang is indicated for such cases.” (from “Shang Han Lun”)

② “When Shang Han presents with a case of Chai Hu syndrome, but only one symptom is present, there is no need to include all symptoms.” (from “Shang Han Lun”)

③ “The formula is named Xiao Chai Hu because it is based on Shaoyang, and its true purpose lies in harmonizing the liver and spleen; as for the principles behind the formula’s formulation and the methods of adjustment, the saying ‘when the upper burner is clear, fluids can descend, and stomach qi can be harmonized’ fully embodies this principle. Why? The Shaoyang meridian runs along the ribs and flanks, between the external and internal aspects of the abdomen; when pathogenic qi enters the interior, it is rejected by the internal qi, so chills come and heat arises; because the exterior and interior oppose each other and remain in the intersection, chest and flank fullness appear; when the spirit refuses and becomes sluggish, a feeling of wanting to eat but unable to arises; when gallbladder fire is blocked and cannot be released, irritability occurs; when heart qi is stagnant and impurities arise, phlegm and stagnation form, so nausea occurs—and when vomiting occurs, both wood and fire are relieved, so the patient feels better. These are all typical symptoms of Shaoyang.” (Cheng Jiao Qian)

④ This formula treated eight cases of postpartum fever, with temperatures consistently above 38°C. Five cases did not respond to antibiotics before treatment, and three cases showed only mild improvement. After taking this formula for 2–5 doses (with an average of 3 doses), all patients recovered. Case R. Liu, female, 28 years old, gave birth to her first child at term, with a pre-pregnancy blood pressure of 150/100 mmHg. She had experienced convulsions once, and on the seventh day after delivery, her temperature suddenly rose to 39.6°C. There was no foul odor in the lochia. White blood cell count was 13,400, with neutrophils accounting for 85%. Antibiotic treatment for 3 days was ineffective; although the lochia was small and not yet completely gone, the abdomen was not swollen, chills and fever alternated, the condition persisted for days, her face and head were swollen, she experienced bitter taste in her mouth, chest discomfort, occasional sighs, a pale red tongue with a thin, greasy coating, and a tense, rapid pulse. Her liver yang was already elevated, and after childbirth, the blood chamber was empty, allowing pathogenic qi to enter and reside in the liver and gallbladder meridians, where Shaoyang qi was unbalanced and the body’s defensive and offensive qi were disrupted. The prescription was as follows: 80% of chai hu fried in vinegar, 3 qian of Sheng Jiang, 1.5 qian of fried Huang Qin, 4 slices of Ren Shen, 3 qian of Dang Gui, 1.5 qian of fried Bai Shao, 3 qian of Zi Dan Shen, 5 fen of Gan Cao, 3 qian of Yimu Cao, 80% of fried Black Jing Jie, and 1 slice of Sheng Jiang. After taking the first dose, the heat and fever subsided. After the second dose, the fever broke (to 37.4°C). After the third dose, the fever disappeared. Finally, a formula for harmonizing and nourishing was used, and after eight doses, the patient recovered. (Shanghai Journal of Traditional Chinese Medicine, 1965.10:14)

[Commentary]

① This formula can also treat women who develop colds and fever during menstruation—these are cases where heat enters the blood chamber.

② Xiao Chai Hu syndrome largely corresponds to modern medical subacute and chronic inflammatory syndromes. For chronic or subacute inflammatory conditions such as chronic cholecystitis, chronic hepatitis, chronic pelvic inflammatory disease, exudative pleurisy, etc., this formula can be used with adjustments.