背为阳，腹为阴。背恶寒，阳不足也。阳不足，则阴气盛。阴气盛者，口中和。阳气内陷者，
口干燥，附子、白虎宜加详审。
口中和，背恶寒者，属少阴，附子汤及灸气海。阳气内陷，口干燥，背恶寒，白虎汤。
寒热往来者，阴阳相胜，邪正相争而作也。盖阳不足，则阴邪出于表而与之争，
故阴胜而为寒。阴不足，则阳邪入于里而与之争，故阳胜而为热。邪居表多，则多寒。邪居里多，
则多热。邪在半表半里，则寒热相半，乍往乍来而间作也。小柴胡汤专主寒热，寒多者，加桂；热
多者，加大黄，是大法也。
太阳病八九日，如疟状，发热恶寒，热多寒少，不呕，清便自可，一日二三度发，桂枝麻黄各
半汤；脉微缓者，不可汗，宜越婢汤。
病至十余日，热结在里，往来寒热，大柴胡汤。心烦发呕，胸膈满，不欲食，寒热往来，小柴胡
汤。
汗下后不呕不渴，头汗出，胸膈满，小便不利，寒热往来，柴胡桂姜汤。
热多寒少，尺脉迟者，荣血不足，黄 建中汤。脉浮大，寒热往来，宜祛邪。
凡妇人中风七八日，续得寒热，发作有时，经水适断，为热入血室，小柴胡汤。
潮热，属阳明，阳明旺于未申，一日一发，日晡而作也。邪入胃腑，为可下之证。设或脉浮而
紧，潮热而利，或小便难，大便溏者，热未入腑，犹带表邪，先当
和解其外。如小便利，大便硬，方可攻之。若潮热于寅卯，寅卯则属少阳，潮于巳午，则属太阳，
是又不可不辩。
病患烦热，汗出则解，又如疟状，日晡潮热，脉实，可下，小承气汤或大柴胡；脉虚者，不可下，
桂枝汤。
阳明病，潮热，大便微硬者，大承气汤。阳明病，脉浮而紧，必潮热，发作有时，但脉浮者，必
盗汗出，柴胡桂枝汤。
腹满，不大便，潮热，小承气汤微利之。
背部属阳，腹部属阴。背部怕冷，是阳气不足的表现。阳气不足，则阴气偏盛。阴气偏盛的人，口中感觉平和（不苦不燥）。如果是阳气内陷的人，则口舌干燥，此时使用附子汤（Aconite Decoction）和白虎汤（White Tiger Decoction）需要仔细审察。
口中感觉平和、背部怕冷的，属于少阴病（Shaoyin Disease），适用附子汤，并可艾灸气海穴（Qihai, CV6）。如果是阳气内陷、口舌干燥且背部怕冷的，适用白虎汤。
寒热往来（交替出现恶寒和发热）的症状，是由于阴阳相互胜负，邪气与正气相争而产生的。大概来说，阳气不足，阴邪出于体表并与正气相争，所以阴胜而表现为恶寒。阴气不足，阳邪入于体内并与正气相争，所以阳胜而表现为发热。邪气多在体表，则恶寒多；邪气多在体内，则发热多。邪气在半表半里之间，则恶寒与发热各占一半，忽冷忽热，间歇性发作。小柴胡汤（Minor Bupleurum Decoction）专门主治寒热往来，恶寒多的，加桂枝（Cinnamon Twig）；发热多的，加大黄（Rhubarb Root and Rhizome），这是基本法则。
太阳病（Taiyang Disease）经过八九日，症状像疟疾一样，发热恶寒，发热多而恶寒少，没有呕吐，大小便正常，一天发作两三次，适用桂枝麻黄各半汤（Guizhi Mahuang Combined Half-Dose Decoction）；如果脉象微缓，不可发汗，适宜用越婢汤（Yuebi Decoction）。
病情发展到十余日，热邪结聚在体内，出现寒热往来，适用大柴胡汤（Major Bupleurum Decoction）。心烦、想吐、胸膈部胀满、不想吃东西、寒热往来，适用小柴胡汤。
经过发汗或攻下治疗后，没有呕吐也没有口渴，只有头部出汗，胸膈部胀满，小便不利，寒热往来，适用柴胡桂姜汤（Bupleurum Coptis and Ginger Decoction）。
发热多而恶寒少，尺脉（Radial Artery Distal Pulse）迟缓的，是营血不足，适用黄芪建中汤（Astragalus Decoctio ad Construing the Middle Jiao）。脉象浮大，寒热往来，适宜祛除邪气。
凡是妇女患中风（Wind Strike）七八日后，持续出现寒热，发作有定时，月经恰好中断，这是热邪陷入血室（Blood Chamber），适用小柴胡汤。
潮热（Tidal Fever），属于阳明病（Yangming Disease）。阳明经气旺盛于未时和申时（下午1点至5点），每天发作一次，在日晡时（下午3点至5点）发作。邪气进入胃腑，属于可以使用攻下法的证候。假如脉象浮而紧，潮热且腹泻，或者小便困难、大便稀溏的，说明热邪尚未完全入腑，仍带有表邪，应当先和解表邪。如小便通畅，大便干硬，才可以攻下。如果潮热发生在寅时和卯时（凌晨3点至7点），寅卯时属少阳经（Shaoyang Channel），潮热发生在巳时和午时（上午9点至下午1点），则属太阳经，这又是不可以不辨别的。
病人烦热，出汗后缓解，又像疟疾一样，日晡时潮热，脉实，可以攻下，用小承气汤（Minor Order the Qi Decoction）或大柴胡汤；脉虚的，不可攻下，用桂枝汤（Cinnamon Twig Decoction）。
阳明病，出现潮热，大便轻微干硬的，用大承气汤（Major Order the Qi Decoction）。阳明病，脉浮而紧，必定会出现潮热，发作有定时，但如果只是脉浮，必定会有盗汗（Night Sweats），用柴胡桂枝汤（Bupleurum and Cinnamon Twig Decoction）。
The back belongs to Yang, and the abdomen belongs to Yin. Cold intolerance of the back indicates insufficiency of Yang Qi. When Yang Qi is insufficient, Yin Qi becomes excessive. In cases of excessive Yin Qi, the mouth feels harmonious (neither bitter nor dry). In cases where Yang Qi has sunk inward, the mouth and tongue are dry; in such instances, careful examination is required before administering Fuzi Tang (Aconite Decoction) or Baihu Tang (White Tiger Decoction).
Cases with a harmonious mouth sensation and cold intolerance of the back belong to Shaoyin Disease. The appropriate treatment is Fuzi Tang, and moxibustion may be applied to Qihai (CV6). For cases where Yang Qi has sunk inward, presenting with a dry mouth and cold intolerance of the back, Baihu Tang is indicated.
Alternating chills and fever (Huanre Wanglai) arise from the mutual victory and defeat of Yin and Yang, and the struggle between pathogenic factors and healthy Qi. Generally, when Yang Qi is insufficient, Yin pathogens emerge at the exterior and contend with healthy Qi, resulting in Yin excess manifesting as chills. When Yin Qi is insufficient, Yang pathogens enter the interior and contend with healthy Qi, resulting in Yang excess manifesting as fever. If pathogens reside mostly at the exterior, chills predominate; if they reside mostly in the interior, fever predominates. If pathogens reside in the half-exterior and half-interior region, chills and fever are equal, occurring intermittently with alternating onset. Xiaochaihu Tang (Minor Bupleurum Decoction) specifically treats alternating chills and fever. If chills predominate, add Guizhi (Cinnamon Twig); if fever predominates, add Dahuang (Rhubarb Root and Rhizome). This constitutes the fundamental principle.
In Taiyang Disease persisting for eight or nine days, symptoms resembling malaria occur: fever and chills, with more fever than chills, no vomiting, normal bowel movements, and episodes occurring two or three times a day. Guizhi Mahuang Ge Ban Tang (Guizhi and Mahuang Combined Half-Dose Decoction) is indicated. If the pulse is slightly slow and relaxed, sweating should not be induced; Yuebi Tang (Yuebi Decoction) is appropriate.
After ten-plus days of illness, if heat is consolidated within the interior accompanied by alternating chills and fever, Da Chaihu Tang (Major Bupleurum Decoction) is indicated. If there is mental restlessness, vomiting, fullness in the chest and diaphragm, anorexia, and alternating chills and fever, Xiaochaihu Tang is indicated.
After perspiration or purgation therapy, if there is no vomiting or thirst, but only sweating on the head, fullness in the chest and diaphragm, dysuria, and alternating chills and fever, Chaihu Guijiang Tang (Bupleurum, Coptis, and Ginger Decoction) is indicated.
If fever predominates over chills and the Chi pulse (distal radial pulse) is slow, this indicates deficiency of Ying Blood (Nutritive Blood). Huangqi Jianzhong Tang (Astragalus Decoctio ad Construing the Middle Jiao) is indicated. If the pulse is floating and large with alternating chills and fever, expelling pathogens is appropriate.
For women suffering from Wind Strike for seven or eight days who subsequently develop alternating chills and fever at regular intervals, coinciding with the sudden cessation of menstruation, this is termed Heat entering the Blood Chamber (Xueshi). Xiaochaihu Tang is indicated.
Tidal Fever (Chaore) belongs to Yangming Disease. Yangming Qi flourishes during the Wei and Shen hours (13:00–17:00). Tidal fever occurs once daily, typically manifesting during the Ribu period (15:00–17:00). Pathogens entering the stomach fu-organ constitute an indication for purgation. However, if the pulse is floating and tight, accompanied by tidal fever and diarrhea, or difficult urination and loose stools, the heat has not fully entered the fu-organ and still carries exterior pathogens; reconciliation of the exterior should be performed first. If urination is clear and stool is hard, purgation may then be administered. If tidal fever occurs during the Yin and Mao hours (03:00–07:00), it relates to the Shaoyang Channel; if it occurs during the Si and Wu hours (09:00–13:00), it relates to the Taiyang Channel. These distinctions must not be overlooked.
If a patient experiences irritability and heat, which resolve after sweating, yet resembles malaria with tidal fever at Ribu time and a solid pulse, purgation is permissible using Xiao Chengqi Tang (Minor Order the Qi Decoction) or Da Chaihu Tang. If the pulse is deficient, purgation is contraindicated; Guizhi Tang is indicated.
In Yangming Disease, if tidal fever is present and the stool is slightly hard, Da Chengqi Tang (Major Order the Qi Decoction) is indicated. In Yangming Disease, if the pulse is floating and tight, tidal fever will inevitably occur at regular intervals. If the pulse is merely floating, night sweats (Daohan) will inevitably occur; Chaihu Guizhi Tang (Bupleurum and Cinnamon Twig Decoction) is indicated.
If abdominal fullness, constipation, and tidal fever are present, Xiao Chengqi Tang should be used to mildly promote bowel movement.