Cheng Wuji: "Wanglai hanre" (alternating chills and fever) refers to the phenomenon where fever arises after chills subside, and chills rise again after fever subsides. This is because cold is Yin, heat is Yang; interior is Yin, exterior is Yang. When pathogenic factors lodge in the exterior and contend with Yang Qi, chills occur; when pathogenic factors enter the interior and contend with Yin Qi, fever occurs. If exterior pathogenic factors are predominant, chills are more frequent than fever; if interior pathogenic factors are predominant, fever is more frequent than chills. When pathogenic factors reside between the exterior and interior, contending outwardly with Yang Qi manifests as chills, and contending inwardly with Yin Qi manifests as fever. Because the Qi of the exterior and interior does not remain fixed in position, and the internal and external Qi lacks a constant measure, the alternating chills and fever occur without regularity. Therefore, Xiao Chai Hu Tang (Minor Bupleurum Decoction) is used to establish various modification methods for harmonization. Additionally, "hanre ru nue" (chills and fever resembling malaria) and "wanglai hanre" (alternating chills and fever) appear similar but are distinct. "Hanre ru nue" refers to episodes that start and stop at specific times; they arise when Zheng Qi (Upright Qi) contends with pathogenic factors and cease when they separate. In contrast, "wanglai hanre" has no fixed timing for onset or cessation; it may occur three to five times or even ten-plus times a day, which differs from malaria. Nevertheless, since alternating chills and fever belong to the Shaoyang syndrome (Half-Exterior Half-Interior Syndrome), harmonization therapy should be employed. Furthermore, if a disease persists for over ten days, with heat consolidated in the interior yet presenting with alternating chills and fever, Da Chai Hu Tang (Major Bupleurum Decoction) should be used to purge and achieve cure.

Zhao Sizhen: Question 59 of *Shanghan Baiwen Ge* (Song on Hundred Questions on Cold Damage) states that when Yin and Yang contend with each other, insufficient Yang leads to chills first followed by fever, while insufficient Yin leads to fever first followed by chills. This specifically discusses the mutual overcoming of Yin and Qi in mixed Yin-Yang diseases and cannot be applied to Shanghan (Cold Damage).

In Shanghan, on the fifth or sixth day, if Wind Strike occurs, presenting with alternating chills and fever, fullness and discomfort in the chest and hypochondrium, silence with lack of desire for food, irritability and propensity to vomit, or alternatively, chest irritability without vomiting, thirst, abdominal pain, hardness and fullness under the hypochondrium, palpitations under the heart with ineffective urination, absence of thirst with slight body heat, or coughing, Xiao Chai Hu Tang (Minor Bupleurum Decoction) is the primary treatment. [Commentary by Cheng Wuji: Diseases can be located in the exterior, in the interior, or between the exterior and interior. Here, pathogenic factors are between the exterior and interior, termed Half-Exterior Half-Interior Syndrome. The fifth or sixth day marks the time when pathogenic factors transmit from the exterior to the interior. "Wind Strike" here means either Wind Strike or Shanghan reaching the fifth or sixth day. The *Yu Han Jing* states: "On the fifth or sixth day of Wind Strike or Shanghan, alternating chills and fever appear," meaning either Wind Strike or Shanghan, not Shanghan contracting Wind Strike again, nor Wind Strike contracting Shanghan again. The Classic says: "In Shanghan or Wind Strike, if Chai Hu patterns exist, observing one symptom suffices; all symptoms need not be present." This precisely refers to either Wind Strike or Shanghan. Exterior pathogens cause chills; interior pathogens cause abdominal heat. Now, with pathogens between the exterior and interior having no fixed location, alternating chills and fever occur. Exterior pathogens do not cause heart/abdominal fullness; interior pathogens cause heart/abdominal distension. Now only chest/diaphragm fullness is mentioned, indicating pathogens are between exterior and interior. The Shaoyang channel runs along the side of the body; the chest and hypochondrium are the domains of Shaoyang. Thus, the Classic states its pulse traverses the hypochondrium and connects to the ears, causing hypochondriac pain and deafness. Silence indicates the pathogen is transitioning from exterior to interior, residing between them, as stated in the *Neijing*: "When Yang enters Yin, there is stillness." Exterior pathogens allow eating; interior pathogens prevent eating. Lack of desire for food indicates pathogens are between exterior and interior, not yet severe enough to completely prevent eating. Exterior pathogens cause no irritability or vomiting; interior pathogens cause irritability, fullness, and vomiting. Irritability and propensity to vomit indicate the pathogen is just transmitting from exterior to interior. Entering the interior newly, with no fixed location, transmission varies, hence various possible symptoms. "Having Chai Hu patterns, observing one symptom suffices" refers exactly to these possible symptoms.] If the original Taiyang disease does not resolve and transmits to Shaoyang, presenting with hardness and fullness under the hypochondrium, dry retching, inability to eat, and alternating chills and fever, provided emesis or purgation has not yet been used and the pulse is deep and tight, administer Xiao Chai Hu Tang (Minor Bupleurum Decoction). [Commentary by Cheng Wuji: Transmission from Taiyang to Shaoyang means exterior pathogens enter the interior. Hardness/fullness under hypochondrium, inability to eat, and alternating chills/fever indicate pathogens are between exterior and interior. If emesis/purgation have already been used and the pulse is deep/tight, pathogens have entered the Fu organs becoming Interior Excess. If emesis/purgation have not been used and the pulse is deep/tight, although transmission to the interior is deep, it has not fully entered the Fu organs, and exterior pathogens remain unresolved. Administer Xiao Chai Hu Tang (Minor Bupleurum Decoction) to harmonize.] If emesis, sweating, or warm needle therapy have already been used, resulting in delirium, and the Chai Hu pattern has ceased, this constitutes a "Huai Bing" (ruined disease). One must determine what error was made and treat accordingly. [Commentary by Cheng Wuji: Pathogens of Shaoyang lie between exterior and interior. Reckless use of emesis, purgation, sweating, or warm needles damages fluids, causing dryness in the Stomach. Wood pathogen attacks the Stomach, inevitably causing delirium. If the Chai Hu pattern persists, it is not an error; if the Chai Hu pattern ceases, it is a ruined disease. Investigate the cause of the therapeutic error and rescue it according to method. To rescue ruined disease and assist Ying/Blood generation and fluid production, seek Guizhi Tang (Cinnamon Twig Decoction).] In Shanghan, on the fifth or sixth day, after sweating has been induced and then purgation applied, presenting with mild consolidation of fullness in the chest and hypochondrium, ineffective urination, thirst without vomiting, only sweat on the head, alternating chills and fever, and irritability, this indicates the disease is unresolved. Chai Hu Guizhi Ganjiang Tang (Bupleurum, Cinnamon Twig, and Dried Ginger Decoction) is the primary treatment. [Nan Zhi said: If Chai Hu Tang is used, after some time, Qi shifts morning and evening, Blood follows Qi, and Qi follows Blood, leaving no place for pathogens to reside, thus knowing resolution is imminent. After sweating and purgation on the fifth or sixth day of Shanghan, pathogens should resolve. Now, with mild consolidation of fullness in chest/hypochondrium, ineffective urination, thirst without vomiting, only head sweat, alternating chills/fever, and irritability, pathogens remain between exterior and interior, indicating unresolved status. Chest/hypochondriac fullness with mild consolidation, chills/fever, and irritability indicate pathogens between exterior and interior. Ineffective urination and thirst indicate loss of fluids due to sweating/purgation, causing internal dryness. If heat consumes fluids causing ineffective urination and thirst, vomiting would necessarily occur. Now, thirst without vomiting indicates this is not Interior Heat. Sweating in Shanghan harmonizes the body; now only head sweats while other areas are dry, indicating insufficient fluids and deficient Yang above. Administer Chai Hu Guizhi Ganjiang Tang (Bupleurum, Cinnamon Twig, and Dried Ginger Decoction) to resolve exterior-interior pathogens and restore fluids to assist Yang.] When Blood is weak and Qi exhausted, pores open, and pathogens enter, contending with Zheng Qi (Upright Qi) and consolidating under the hypochondrium. Zheng and Xie contend, causing alternating chills and fever with periodic onset and cessation, silence, and lack of desire for food. Zang and Fu are connected; pain must follow downward. Pathogens are high, pain is low, thus causing vomiting. Xiao Chai Hu Tang (Minor Bupleurum Decoction) is the primary treatment. [Note: From "Blood weak, Qi exhausted" to "consolidating under hypochondrium" explains "fullness and discomfort in chest and hypochondrium"; "Zheng and Xie contend" three sentences explain "alternating chills and fever" using inverted syntax. "Silence and lack of desire for food" combines with previous fullness/pain. "Zang and Fu connected" four sentences explain "irritability and propensity to vomit".]

Xiao Chai Hu Tang (Minor Bupleurum Decoction) Formula: Chai Hu (Bupleuri Radix, 8 liang), Ban Xia (Pinelliae Rhizoma prepared with hot water, half sheng), Ren Shen (Ginseng Radix et Rhizoma), Gan Cao (Glycyrrhizae Radix et Rhizoma), Huang Qin (Scutellariae Radix), Sheng Jiang (Zingiberis Rhizoma Recens, 3 liang each), Da Zao (Jujubae Fructus, 12 pieces, split). These seven ingredients are boiled in 12 sheng of water to obtain 6 sheng, strained, and decocted again to yield 3 sheng. Take 1 sheng warm, three times daily. [Commentary by Cheng Wuji: The *Neijing* states "Heat rampant within, disperse with bitter." The bitterness of Chai Hu and Huang Qin disperses transmitted heat. For interior deficiency, soothe with sweet; the sweetness of Ren Shen and Gan Cao moderates central Qi. When pathogens semi-enter the interior, interior Qi rebels; pungent herbs disperse them, Ban Xia stops vomiting. When pathogens are half-exterior, Ying and Wei contend; pungent-sweet herbs resolve them, Ginger and Jujube harmonize Ying and Wei.]

Modification Methods (for Shaoyang pathogens in the chest): If chest irritability without vomiting, remove Ban Xia (Pinelliae Rhizoma), add Gua Lou Shi (Trichosanthis Fructus, 1 piece). [Chest irritability without vomiting indicates heat aggregation without Qi rebellion. Sweet herbs cause fullness; since heat aggregates, avoid Ren Shen's tonification. Pungent herbs disperse rebellious Qi; since no vomiting, avoid Ban Xia's pungency. Heat requires cold treatment; aggregated heat requires bitter drainage. Gua Lou is bitter-cold, draining chest heat.] If thirsty, remove Ban Xia (Pinelliae Rhizoma), increase Ren Shen (Ginseng Radix et Rhizoma) to total 4.5 liang, add Gua Lou Gen (Trichosanthis Radix, 4 liang). [Ban Xia dries fluids, unsuitable for thirst; Ren Shen is sweet-moistening; Gua Lou Gen is bitter-cooling, clearing heat and generating fluids; these two are appropriate.] If abdominal pain, remove Huang Qin (Scutellariae Radix), add Shao Yao (Paeoniae Radix Alba, 3 liang). [Remove Huang Qin to avoid harming middle Jiao cold; add Shao Yao to unblock stagnation. Unblocking stagnation has less effect, stopping pain has greater effect.] If hardness and fullness under hypochondrium, remove Da Zao (Jujubae Fructus), add Mu Li (Ostreae Concha, 4 liang). [Sweet herbs cause fullness; remove Da Zao's sweetness for fullness. Salty herbs soften hardness; add Mu Li's salinity for hardness.] If palpitations under the heart with ineffective urination, remove Huang Qin (Scutellariae Radix), add Fu Ling (Poria, 4 liang). [Fluid retention causes palpitations and ineffective urination. The *Neijing* states "Kidney desires firmness, urgently feed bitter to firm Kidney." Bitter makes Water firm in Kidney, so remove Huang Qin. Light/bland flavors drain yang; Fu Ling is sweet-bland, draining retained water.] If not thirsty with slight exterior heat, remove Ren Shen (Ginseng Radix et Rhizoma), add Gui Zhi (Cinnamomi Ramulus, 3 liang), cover warmly to induce slight sweating for cure. [No thirst indicates interior harmony, so remove Ren Shen. Slight exterior heat indicates unresolved exterior, add Gui Zhi to induce sweating.] If coughing, remove Ren Shen (Ginseng Radix et Rhizoma), Da Zao (Jujubae Fructus), Sheng Jiang (Zingiberis Rhizoma Recens), add Wu Wei Zi (Schisandrae Fructus, half sheng), Gan Jiang (Zingiberis Rhizoma, 2 liang). [Coughing indicates Qi rebellion. Sweet herbs obstruct Qi, so remove Ren Shen and Da Zao. The *Neijing* states "Lung desires astringency, urgently feed sour to astringe." Wu Wei Zi's sourness astringes rebellious Qi. Lung cold causes coughing; disperse cold with pungent-hot, so replace Sheng Jiang with Gan Jiang's heat.]

For Shanghan, pathogens in the exterior must be treated by inducing sweating through soaking the body; pathogens in the interior must be treated by purging to promote bowel movement. For those neither purely exterior nor purely interior, i.e., Half-Exterior Half-Interior, harmonization is appropriate. Xiao Chai Hu Tang (Minor Bupleurum Decoction) is a formula for harmonizing exterior and interior. The *Neijing* states "Heat rampant within, disperse with bitter." Pathogens between exterior and interior become half-heat; internal transmission of heat is unpredictable, requiring preemptive interception and dissipation, primarily using bitter-cold herbs. Thus, Chai Hu is the Sovereign herb, Huang Qin is the Minister herb, forming a formula to clear heat and release the exterior. When pathogens transmit to the interior, interior Qi becomes disordered, so Ren Shen and Gan Cao are used as Sovereigns to support Zheng Qi (Upright Qi) and restore it. Newly entering the interior, Qi rebels, so pungent-dispersing herbs assist; Ban Xia is the Assistant herb to smooth rebellious Qi and disperse pathogens. When interior Qi is balanced, pathogens cannot penetrate deeply; these three herbs assist Chai Hu to harmonize the interior. The *Neijing* states "Pungent-sweet disperses Yang." If exterior pathogens persist and gradually transmit internally without becoming excess, both exterior and interior should be resolved. The exterior component requires pungent-sweet dispersion, so Sheng Jiang and Da Zao are the Envoys, assisting Chai Hu to harmonize the exterior. The combination of seven ingredients forms an appropriate dual-resolving formula. Pathogens from the exterior do not consolidate into excess immediately; invading via deficiency, transmission varies, hence modifications are needed. Chest irritability without vomiting: irritability is heat, vomiting is Qi rebellion. Irritability without vomiting means heat aggregates without Qi rebellion, pathogens gradually becoming excess. Remove sweet-tonifying Ren Shen to avoid aiding heat; remove pungent-dispersing Ban Xia as there is no Qi rebellion. Clear heat with cold, drain heat with bitter, add Gua Lou Shi to unblock chest郁热 (depressed heat). If thirsty, fluids are insufficient. Ban Xia is pungent-dry, depleting fluids; remove it so fluids regenerate. Ren Shen is sweet-moistening; Gua Lou Gen is bitter-firming. Firmness and moisture combine to generate fluids, curing thirst. Pathogens entering the interior cause interior deficiency, leading to stagnation-cold and abdominal pain. Huang Qin is bitter-cold; removing it allows Qi to harmonize. Shao Yao is sour-draining and beneficial to the middle; adding it unblocks interior Qi, curing pain. The *Neijing* states "Sweet causes fullness." Remove sweet-warm Da Zao to dissipate hardness-fullness. Salty softens hardness; add sour-salty-cold Mu Li to eliminate fullness and soften hardness. If palpitations and ineffective urination, water retains and fails to move. The *Neijing* states "Kidney desires firmness, urgently feed bitter to firm it." Firming Kidney makes Water firm; remove bitter-cold Huang Qin to prevent water infiltration. The *Ling Shu* states "Bland flavors drain and leak yang." Add sweet-bland Fu Ling to flow fluids. If not thirsty with slight exterior heat: no thirst means sufficient fluids, remove Ren Shen (an interior tonic); slight exterior heat means many exterior signs, add Gui Zhi to induce sweating and disperse exterior pathogens. If coughing, Lung Qi rebels. Sweet tonification in the middle exacerbates Qi rebellion, so remove sweet Ren Shen and Da Zao. Lung desires astringency, urgently feed sour to astringe; rebellious Qi needs astringing, so add sour Wu Wei Zi. Cough originates from cold; internal invasion of cold requires dispersal with pungent-hot Gan Jiang. Sheng Jiang and Gan Jiang are the same plant; fresh is warm, dried is hot, so replace fresh with dried.

Wu Kun: Someone asked about Xiao Chai Hu Tang (Minor Bupleurum Decoction): why do modern practitioners use it for Shanghan fever without distinguishing Yin and Yang? However, the bitter-ping nature of Chai Hu is a herb for Shaoyang channel Shanghan fever, removing half-exterior half-interior heat and alternating chills/fever, with slight afternoon tidal fever. Assisted by bitter-cold Huang Qin to reduce heat, pungent Ban Xia and Sheng Jiang to reduce cold, sweet-warm Ren Shen and Da Zao to assist Zheng Qi (Upright Qi), relieve thirst, and generate fluids, Yin and Yang harmonize and pathogens resolve. But Taiyang exterior heat and Yangming meridian marked heat cannot be resolved. Using it, how can one say it is harmless? If patients have Yang deficiency cold, red face, fever, deep pulse, and cold feet, administering it leads to critical danger immediately. Must be cautious! Also, internal deficiency with cold, loose stools, small-weak pulse, and postpartum fever in women are all contraindications.

If a Chai Hu Tang pattern is treated with purgation, and the Chai Hu pattern persists, re-administering Xiao Chai Hu Tang (Minor Bupleurum Decoction) will likely cause shivering with internal heat sensation, followed by fever, sweating, and resolution. [Commentary by Cheng Wuji: Pathogens between exterior and interior constitute a Chai Hu pattern, not yet Interior Excess. If the physician uses purgatives, and the Chai Hu pattern remains, purgation is not adverse. Re-administer Xiao Chai Hu Tang (Minor Bupleurum Decoction) to harmonize. After taking the decoction, pathogens return to the exterior, manifesting as internal heat sensation ("zheng zheng") and external heat. Having previously purged, the interior is deficient; pathogens seeking exit cause internal trembling ("zhen zhen"). When Zheng Qi (Upright Qi) prevails and Yang Qi generates, fever returns, sweating occurs, and the disease resolves.] In Shanghan or Wind Strike, if Chai Hu patterns exist, observing one symptom suffices; all symptoms need not be present. [Chai Hu patterns indicate pathogens between exterior and interior. Possible symptoms include chest irritability without vomiting, thirst, abdominal pain, hardness/fullness under hypochondrium, palpitations/ineffective urination, no thirst/slight body heat, or cough. Observing one symptom, promptly administer Xiao Chai Hu Tang (Minor Bupleurum Decoction), treating according to the specific symptom. There is no need to wait for all symptoms to appear.]

In Shanghan, after ten-plus days, with heat consolidated in the interior and recurring alternating chills and fever, administer Da Chai Hu Tang (Major Bupleurum Decoction). If Jie Xiong (Chest Binding) presents without significant heat, this is Water Binding in the chest and hypochondrium, with only slight head sweating; Da Xian Xiong Tang (Major Decoction to Drain the Chest) is the primary treatment. [See Jie Xiong section.]

Da Chai Hu Tang (Major Bupleurum Decoction) Formula: Chai Hu (Bupleuri Radix, 8 liang), Ban Xia (Pinelliae Rhizoma, half sheng, washed), Huang Qin (Scutellariae Radix), Shao Yao (Paeoniae Radix Alba, 3 liang each), Sheng Jiang (Zingiberis Rhizoma Recens, sliced, 5 liang), Da Zao (Jujubae Fructus, 12 pieces, split), Zhi Shi (Aurantii Fructus Immaturus roasted, 4 pieces). These seven ingredients are boiled in 12 sheng of water to obtain 6 sheng, strained, and decocted again to yield 3 sheng. Take 1 sheng warm, three times daily. Another version includes Da Huang (Rhei Radix et Rhizoma, 2 liang); without Da Huang, it may not be considered Da Chai Hu Tang (Major Bupleurum Decoction).

Cheng Wuji: Formulas vary in severity, slowness, lightness, and heaviness; physicians must adjust according to circumstances. For severe fullness, excess, hardness, and dry stool, strong purgatives are required to drain, hence the harshness of Xiao Cheng Qi Tang (Minor Order the Qi Decoction) and Da Cheng Qi Tang (Major Order the Qi Decoction). If not severely hard/full, but only extreme pathogenic heat requiring purgation, Cheng Qi Tang formulas are inappropriate; a milder formula like Da Chai Hu Tang (Major Bupleurum Decoction) is needed to drive out pathogenic heat. The Classic states: "Shanghan with fever for seven-eight days, even if pulse is floating-numerous, purgation is permissible, suitable for Da Chai Hu Tang (Major Bupleurum Decoction)." Also: "Taiyang disease passing beyond its period for ten-plus days, mistakenly purged two-three times, on the fourth-fifth day, if Chai Hu patterns persist, first give Xiao Chai Hu Tang (Minor Bupleurum Decoction). If retching continues, urgency under the heart, and slight vexation indicate unresolved status; give Da Chai Hu Tang (Major Bupleurum Decoction) to purge for cure." Thus, Da Chai Hu Tang (Major Bupleurum Decoction) is known as the mild purgative. Shanghan requiring purgation indicates excess heat, corresponding to Fire returning to Heart. Bitter enters Heart first; reducing heat requires bitter as primary. Thus, Chai Hu (bitter-ping, slightly cold) is Sovereign, Huang Qin (bitter-cold) is Minister. The *Neijing* states "Sour-bitter涌泄 (surge and drain) is Yin." Draining excess and reducing heat requires sour-bitter, so Shao Yao and Zhi Shi are Assistants. Pungent disperses; dispersing rebellious Qi requires pungent. Sweet moderates; moderating Zheng Qi (Upright Qi) requires sweet. Thus, pungent-warm Ban Xia and Sheng Jiang, and sweet-warm Da Zao are Envoys. Another version adds Da Huang (Rhei Radix et Rhizoma); Da Huang has the title "General" and specializes in scouring, so it must be the Envoy.

Xu Shimian: A patient had Shanghan with irritability, propensity to vomit, and alternating chills and fever. The physician gave Xiao Chai Hu Tang (Minor Bupleurum Decoction), but it did not resolve. I said: The pulse is large and solid, heat is consolidated in the interior. How can Xiao Chai Hu Tang (Minor Bupleurum Decoction) remove it? Zhongjing said: "Shanghan for ten-plus days, heat consolidated in the interior with recurring alternating chills and fever, give Da Chai Hu Tang (Major Bupleurum Decoction)." After three doses, the disease cleared. Da Huang (Rhei Radix et Rhizoma) scours accumulated heat; it is a crucial herb for Shanghan. Wang Shuhe said: "Without Da Huang (Rhei Radix et Rhizoma), it cannot be named Da Chai Hu Tang (Major Bupleurum Decoction)." It must be wine-washed and used raw for efficacy.

Zhang Yuansu: Someone asked about Da Chai Hu Tang (Major Bupleurum Decoction): it is indeed suitable for internal vexation and interior excess, but why use it for vomiting with diarrhea? Treating disease involves two categories: deficiency and excess. For interior deficiency, even with difficult stool, do not attack. For interior excess, even with vomiting/diarrhea, purgation is permissible. The Classic states: "Excessive sweating leads to difficult stool; if pulse is slow, purgation is not yet permissible, because slowness indicates insufficiency, i.e., interior Qi is not yet excess." This case is treated with Da Chai Hu Tang (Major Bupleurum Decoction). Generally, vomiting/diarrhea with soft abdomen indicates interior deficiency; vomiting/diarrhea with epigastric hardness/fullness indicates interior excess, warranting purgation. Moreover, Taiyang disease passing beyond its period for ten-plus days, mistakenly purged two-three times, on the fourth-fifth day, if Chai Hu patterns persist, first give Xiao Chai Hu Tang (Minor Bupleurum Decoction). If retching continues, urgency under the heart, and slight vexation indicate unresolved status, give Da Chai Hu Tang (Major Bupleurum Decoction) to purge for cure. However, continuous retching with slight vexation indicates extreme interior heat consolidating in the Stomach, so purging cures it. Although these two cases differ slightly, their interior excess mechanism is identical; both appropriately receive Da Chai Hu Tang (Major Bupleurum Decoction).

In Shanghan, on the fifth or sixth day, after sweating and then purgation, presenting with mild consolidation of fullness in chest/hypochondrium, ineffective urination, thirst without vomiting, only head sweat, alternating chills and fever, and irritability, this indicates unresolved status. Chai Hu Guizhi Ganjiang Tang (Bupleurum, Cinnamon Twig, and Dried Ginger Decoction) is the primary treatment. [Sweating then purging follows the correct sequence of releasing exterior then attacking interior, but purging when sweating was indicated is improper. After sweating, pathogens should scatter; failing to wait for full resolution and purging prematurely causes consolidation. Why wouldn't it consolidate? However, after sweating, pathogenic force is weakened; although purging was premature, consolidation should be mild. Cheng's commentary was unclear, so I clarify.]

Chai Hu Guizhi Ganjiang Tang (Bupleurum, Cinnamon Twig, and Dried Ginger Decoction) Formula: Chai Hu (Bupleuri Radix, 8 liang), Gua Lou Gen (Trichosanthis Radix, 4 liang), Gui Zhi (Cinnamomi Ramulus, bark removed, 3 liang), Mu Li (Ostreae Concha), Gan Jiang (Zingiberis Rhizoma), Huang Qin (Scutellariae Radix, 2 liang each), Gan Cao (Glycyrrhizae Radix et Rhizoma roasted, 1 liang). These seven ingredients are boiled in 12 sheng of water to obtain 6 sheng, strained, and decocted again to yield 3 sheng. Take 1 sheng warm, three times daily. Initial dose causes slight vexation; subsequent doses induce sweating and cure. [Commentary by Cheng Wuji: The *Neijing* states "Heat rampant within, disperse with bitter." Bitter Chai Hu and Huang Qin resolve transmitted interior pathogens. Pungent-sweet disperses Yang; pungent-sweet Gui Zhi and Gan Cao disperse exterior pathogens. Salty softens; salty Mu Li eliminates chest/hypochondriac fullness. Pungent moistens; pungent Gan Jiang secures Yang-deficient sweating. Fluid deficiency causes thirst; bitter firms, bitter Gua Lou generates fluids.]

If a patient's pulse is micro and choppy, this is iatrogenic injury. Profuse sweating followed by repeated heavy purgation causes blood depletion. The patient should feel chills, then fever, without cessation. In summer heat, desiring heavy clothing; in winter cold, desiring to strip naked. The reason: Yang deficiency causes chills; Yin weakness causes fever. The physician's profuse sweating made Yang Qi weak, and heavy purgation made Yin Qi weak. In the fifth month, Yang Qi is in the exterior, Stomach is empty and cold; internal Yang deficiency cannot overcome cold, hence desiring heavy clothing. In the eleventh month, Yang Qi is in the interior, Stomach is烦热 (vexed-heat); internal Yin weakness cannot overcome heat, hence desiring to strip naked. Also, Yin pulse is slow-choppy, confirming blood loss.) The micro pulse results from profuse sweating, so during chills, even in midsummer, heavy clothing is desired. The choppy pulse results from heavy purgation, so during post-chill fever, even in midwinter, stripping naked is desired. All these result from blood loss, Yang deficiency, and Yin weakness, unable to overcome cold or heat, not merely extending midsummer to midwinter.]