少阳之为病，口苦咽干目眩也。
按少阳从相火化气，其经在阳明之次， 脉之分，起目锐 ，循耳下项，自胸贯膈，由胁里出外踝，
循足跗而走名指。病则经气壅迫，不能顺降，故胸痛胁痞，相火上炎，故口苦咽干，阳气升浮，是以目眩，
浊气充塞，是以耳聋。位在二阳之里，三阴之表，阳盛则热，阴盛则寒，故往来寒热。其视三阳之经，阳气
方长，故其脉弦细。伤寒中风，一日太阳，二日阳明，三日则传少阳。然三日少阳，而不入阳明之腑。太
阴之脏，则无少阳诸证。六日经尽汗出表解，不能自解，则以麻黄桂枝发之，大小柴胡不必用也。若内传脏腑，
外连少阳之经，然后显少阳诸证，其始得不必三日，其病解不必六日，大小柴胡之的证，于太阳之麻桂无关
矣。
按少阳经本病，经气郁迫，表里不和，以小柴胡汤主之。太阳经证未罢，而遽入少阳，以柴胡桂枝汤主
之。太阳病未解而表实，以麻黄汤主之。少阳病已具而里虚，以小建中汤主之。太少合病，而自下利，以
黄芩汤主之。若呕者，黄芩加半夏生姜汤主之。表未解而里实，以大柴胡
汤主之。表已解而里热，以调胃承气汤主之。妇人热入血室，以小柴胡汤主之。
本太阳病不解，转入少阳者，胁下硬满，干呕不能食。往来寒热，尚未吐下，脉沉紧者，与小柴胡
汤。若已吐下发汗、温针、谵语，柴胡证罢，此为坏病。知犯何逆。以法治之。
按少阳在阴阳之交，表里之半，忌发汗、吐、下，泄其阴阳。阳虚而入太阴之脏，阴虚而入阳明之
腑，是为少阳坏病。如太阳病不能汗解，转入少阳，胁下硬满，干呕不食，往来寒热，若尚未吐下，其脉
沉紧者，全是小柴胡汤证，宜与小柴胡汤。若已经发汗、吐、下、温针以致谵语不明，柴胡证罢，此少阳
之坏病也。审其汗、下、温针所犯何逆，以治之，救其坏也。
按少阳坏病入阳明，去路里虚而心悸烦，以小建中汤主之。里虚而心动悸，以炙甘草汤主之。里虚而
烦满谵语，以柴胡加龙骨牡蛎汤主之。少阳本病未罢，仍以小柴胡汤主之。表未解而里实，仍以大柴胡汤
主之。表未解而里热，以柴胡加芒硝汤主之。入太阴去路表里未解，以柴胡桂枝干姜汤主之。
按：少阳经以相火（寄居于胆和三焦的命门之火）化生其气，该经脉位于阳明经之后，循行于两胁部位，起始于目外眦，沿耳下经过颈部，从胸部贯穿膈肌，由胁肋内部出于体表，再沿足背行走至第四趾。发病时经气壅滞紧迫，不能顺降，所以出现胸痛、胁部痞塞；相火上炎，所以口苦、咽干；阳气升浮，因此头晕目眩；浊气充塞，所以耳聋。少阳位居阳明之里、三阴之表，阳气盛则发热，阴气盛则恶寒，所以表现为忽冷忽热。观察三阳经的脉象，此时阳气正在生长，所以脉象弦而细。伤寒或中风病，第一天在太阳经，第二天传至阳明经，第三天则传入少阳经。然而到了第三天传入少阳，却不进入阳明腑。如果传入太阴脏，则不会出现少阳的各种证候。六天经气运行完毕，若汗出而表证解除，但不能自愈，则用麻黄汤和桂枝汤发汗解表，不需要使用大柴胡汤或小柴胡汤。如果病邪内传脏腑，外连少阳经脉，然后才显现少阳的各种证候，那么发病不一定在第三天，病愈也不一定在第六天，大柴胡汤和小柴胡汤的确切适应证，与太阳病的麻黄汤、桂枝汤就没有关系了。
按：少阳经的本病，是经气郁结紧迫，表里不和，用小柴胡汤主治。太阳经证尚未罢除，就迅速传入少阳，用柴胡桂枝汤主治。太阳病未解除且表实证明显，用麻黄汤主治。少阳病已具备但里虚证明显，用小建中汤主治。太阳与少阳合病，出现自发性腹泻，用黄芩汤主治。如果有呕吐症状，用黄芩加半夏生姜汤主治。表证未解且里实证明显，用大柴胡汤主治。表证已解且里有热，用调胃承气汤主治。妇女热邪陷入血室，用小柴胡汤主治。
原本太阳病未解除，转入少阳的，表现为胁下硬满，干呕不能进食，忽冷忽热，如果尚未使用吐法或下法，脉象沉紧的，给予小柴胡汤。如果已经使用了吐法、发汗、温针，导致谵语，柴胡证已消失，这称为坏病。需查明犯了什么错误，根据具体情况治疗。
按：少阳处于阴阳交接、表里半表半里的位置，忌讳使用发汗、催吐、泻下法，以免损伤阴阳。阳气虚弱则传入太阴脏，阴液亏虚则传入阳明腑，这就是少阳坏病。如太阳病不能用汗法解除，转入少阳，出现胁下硬满，干呕不食，忽冷忽热，如果尚未使用吐法或下法，脉象沉紧的，完全是小柴胡汤的适应证，适宜给予小柴胡汤。如果已经经过发汗、催吐、泻下、温针等误治，导致神志不清、谵语，柴胡证已消失，这是少阳的坏病。审察汗、下、温针所犯的错误是什么，进行针对性治疗，以挽救坏病。
按：少阳坏病传入阳明，去路里虚而出现心悸、心烦，用小建中汤主治。里虚而出现心跳悸动不安，用炙甘草汤主治。里虚而出现心烦、胀满、谵语，用柴胡加龙骨牡蛎汤主治。少阳本病尚未消除，仍用小柴胡汤主治。表证未解且里实证明显，仍用大柴胡汤主治。表证未解且里有热，用柴胡加芒硝汤主治。传入太阴去路，表里证均未解除，用柴胡桂枝干姜汤主治。
The disease of the Shaoyang (Lesser Yang) channel is characterized by bitter taste in the mouth, dryness of the throat, and vertigo.
Note: The Shaoyang channel transforms Qi according to Xianghuo (Ministerial Fire). Its course lies posterior to the Yangming channel, traversing the hypochondriac region. It originates at the outer canthus of the eye, follows down along the ear to the neck, passes through the chest piercing the diaphragm, emerges from the interior of the hypochondrium to the exterior, then follows the dorsum of the foot to the fourth toe. When diseased, the channel Qi becomes stagnant and constrained, failing to descend smoothly, resulting in chest pain and hypochondriac fullness/stagnation. Ministerial Fire flares upward, causing bitter taste and dry throat; Yang Qi floats upward, leading to vertigo; turbid Qi obstructs, causing deafness. Located interior to the two Yang channels and exterior to the three Yin channels, excess Yang leads to heat, while excess Yin leads to cold, hence alternating chills and fever. Observing the three Yang channels, as Yang Qi is growing, the pulse is wiry and fine. In Cold Damage or Wind Strike, on the first day it affects the Taiyang (Greater Yang) channel, on the second day the Yangming (Yang Brightness) channel, and on the third day it transmits to the Shaoyang channel. However, on the third day, if it enters Shaoyang but does not enter the Yangming Fu organs, and if it enters the Taiyin Zang organs, the various Shaoyang syndromes will not appear. After six days, when the meridian cycle completes, if sweating occurs and the exterior resolves but self-resolution fails, Ma Huang Tang (Ephedra Decoction) and Gui Zhi Tang (Cinnamon Twig Decoction) should be used to induce sweating; Da Chai Hu Tang (Major Bupleurum Decoction) and Xiao Chai Hu Tang (Minor Bupleurum Decoction) are not necessary. If the pathogen transmits internally to the Zang-Fu organs and externally connects with the Shaoyang channel, only then do the various Shaoyang syndromes manifest. In such cases, onset need not be on the third day, nor resolution on the sixth day. The specific indications for Da Chai Hu Tang and Xiao Chai Hu Tang are unrelated to the Ma Huang Tang and Gui Zhi Tang of the Taiyang stage.
Note: For the primary disease of the Shaoyang channel, where channel Qi is constrained and interior-exterior disharmony exists, Xiao Chai Hu Tang (Minor Bupleurum Decoction) is the principal formula. If the Taiyang exterior syndrome has not yet resolved but quickly transmits to Shaoyang, Chai Hu Gui Zhi Tang (Bupleurum and Cinnamon Twig Decoction) is indicated. If the Taiyang disease remains unresolved with an exterior excess pattern, Ma Huang Tang (Ephedra Decoction) is used. If the Shaoyang disease is established but there is interior deficiency, Xiao Jian Zhong Tang (Minor Construct the Middle Decoction) is used. In a combined Taiyin-Shaoyang disease presenting with spontaneous diarrhea, Huang Qin Tang (Scutellaria Decoction) is indicated. If vomiting is present, Huang Qin Jia Ban Xia Sheng Jiang Tang (Scutellaria Decoction plus Pinellia and Fresh Ginger) is used. If the exterior is unresolved and there is interior excess, Da Chai Hu Tang (Major Bupleurum Decoction) is used. If the exterior has resolved and there is interior heat, Tiao Wei Cheng Qi Tang (Regulate the Stomach and Direct Downward Decoction) is used. For women with Heat entering the Blood Chamber, Xiao Chai Hu Tang (Minor Bupleurum Decoction) is used.
If the original Taiyang disease remains unresolved and transmits to Shaoyang, presenting with hardness and fullness below the costal margin, dry retching, inability to eat, and alternating chills and fever, if emesis or purgation has not yet been used and the pulse is deep and tight, administer Xiao Chai Hu Tang (Minor Bupleurum Decoction). If emesis, sweating, warm needle therapy have already been applied, leading to delirious speech, and the Chai Hu syndrome has ceased, this is termed a "Huai Bing" (Complicated/Mishandled Disease). Determine what error was committed and treat accordingly.
Note: Shaoyang resides at the intersection of Yin and Yang, half-exterior and half-interior. Sweating, emesis, and purgation are contraindicated as they deplete Yin and Yang. If Yang becomes deficient, the pathogen enters the Taiyin Zang organs; if Yin becomes deficient, it enters the Yangming Fu organs; this constitutes a Shaoyang Huai Bing (Complicated Disease). For instance, if Taiyang disease cannot be resolved by sweating and transmits to Shaoyang, presenting with hardness/fullness below the costal margin, dry retching, anorexia, and alternating chills/fever, if emesis/purgation have not been used and the pulse is deep/tight, it is entirely a Xiao Chai Hu Tang (Minor Bupleurum Decoction) syndrome, and this decoction should be administered. If sweating, emesis, purgation, or warm needles have already been used, resulting in confusion and delirium, and the Chai Hu syndrome has ceased, this is a Shaoyang Huai Bing. Investigate the errors committed via sweating, purgation, or warm needles and treat them to salvage the complicated condition.
Note: If a Shaoyang Huai Bing transmits to Yangming, and the pathway shows interior deficiency with palpitations and vexation, Xiao Jian Zhong Tang (Minor Construct the Middle Decoction) is used. If interior deficiency presents with palpitations, Zhi Gan Cao Tang (Honey-Fried Licorice Decoction) is used. If interior deficiency presents with vexation, fullness, and delirium, Chai Hu Jia Long Gu Mu Li Tang (Bupleurum plus Dragon Bone and Oyster Shell Decoction) is used. If the primary Shaoyang disease has not ceased, continue using Xiao Chai Hu Tang (Minor Bupleurum Decoction). If the exterior is unresolved with interior excess, use Da Chai Hu Tang (Major Bupleurum Decoction). If the exterior is unresolved with interior heat, use Chai Hu Jia Mang Xiao Tang (Bupleurum plus Mirabilite Decoction). If transmitting to the Taiyin pathway with both exterior and interior unresolved, Chai Hu Gui Zhi Gan Jiang Tang (Bupleurum, Cinnamon Twig, and Dried Ginger Decoction) is used.