下后有热，血气虚也，太阳阳明之故也。仲景云∶大发其汗，使阳气微，又下之，使
阴气弱，其人亡血，病当寒后乃发热无休止，阴阳既虚，气血俱弱，故其热不可止息。所
用葶苈、栀子，亦酸苦涌泄之义也。
【吐】阳明下之，仍发热，心下懊 ，饥不能食，头汗出，栀子豉汤。
【利】服桂枝汤，或下之，仍头项强，无汗，翕翕发热，心下满，微痛，小便不
利，桂枝汤去桂加茯苓白术汤。
【壮阴】大下后则伤血，故脉涩，葶苈苦酒汤。
汗后恶寒，但表解未尽，则为轻证，法当再汗之。若阳微于外，寒积于内，厥逆自
利，则用四逆汤。若阳微于外，热伏于内，大便实者，下之。若汗后脉不为汗衰，比前躁
疾者，此名阴阳交，交者死。（此篇可与不得汗及前恶寒兼看。）
【发表】汗后恶寒，表未解者，汗之，麻黄汤。
【两解】汗后热不退，大便宜，微恶寒者，先解表，表解后用大柴胡汤、小承气汤。
【温】汗后阳微恶寒，大便不实者，芍药附子甘草汤。汗后恶寒自利厥逆者，四逆汤。
三法俱用之后而病不愈者，其有虚实之故也。若非余邪未尽，必是阴阳两虚。于斯时
也，当斟酌审之，或可泻则泻，可补则补，庶不杀人也。
【和】五六日已发汗复下之，胸胁满，微结，小便不利，渴而不呕，但头汗出，往来
寒热，心烦，为未解，柴胡桂姜汤。太阳汗吐下解后心下痞硬，噫气不除，旋复代赭石汤。
【解】太阳先发汗不解，而复下之，脉浮者，则知病在外，当须解外，桂枝汤。
【清】吐下后七八日不解、热结在里，表里俱热，时时恶风，大渴，舌上干烦饮水者，
白虎加人参汤。
【温】汗下之后病仍不解，躁烦不得眠，茯苓四逆汤。大汗若大利而厥者，四逆汤。
下后复发汗，昼日烦躁不得眠，夜而安静，不呕不渴，无表证，脉沉微，身无大热，干姜附
子汤。下后复发汗，脉微细而振寒者，此内外俱虚也。吐下之后，食入口即吐，干姜黄连
黄芩人参汤。
【吐】发汗吐下后，虚烦不眠，剧者反复颠倒，心中懊 ，栀子豉汤。发汗若下之，烦
热胸中窒，栀子豉汤。
【下】吐下后不大便，五六日至十余日，日晡发潮热，不恶寒，独误如见鬼，循衣
摸床，脉弦者生，涩者死；但发热谵语，大承气汤。吐下后腹胀者，邪热入胃也，调胃承
气汤。太阳吐下后微烦，小便数，大便硬，小承气汤。
【和经益阳】吐下后心下逆满，气上冲胸，头眩，脉沉紧，发汗则动经，身为振摇，茯
苓桂枝白术甘草汤。
[After Purging: Heat]
Heat appearing after purgation is due to the deficiency of blood and qi, involving the Taiyang (Greater Yang) and Yangming (Yang Brightness) channels. Zhang Zhongjing stated: Profuse sweating causes yang qi to become weak; subsequent purgation causes yin qi to become weak. The person loses blood, and the condition manifests as alternating chills and fever without cessation. Since both yin and yang are deficient, and blood and qi are both weak, this heat cannot stop. The use of Lepidium seed (Tingli) and Gardenia fruit (Zhizi) also conforms to the principle of sour and bitter inducing emesis or purgation.
[Regarding Emesis]
In Yangming disease, after purgation, if fever persists, accompanied by oppression in the epigastrium with restlessness, hunger but inability to eat, and sweating only on the head, Zhi Zi Chi Tang (Gardenia and Fermented Soybean Decoction) is indicated.
[Regarding Purgation/Diuresis]
After taking Guizhi Tang (Cinnamon Twig Decoction), or after purgation, if there is still stiffness and pain in the head and nape, absence of sweat, slight fever resembling a feather's touch, fullness in the epigastrium, mild pain, and difficulty in urination, Guizhi Tang (Cinnamon Twig Decoction) with Gui (Cinnamon Twig) removed, plus Fu Ling (Poria) and Bai Zhu (Atractylodes Macrocephala Rhizome) added is indicated.
[Strengthening Yin]
Profuse purgation damages blood, resulting in a choppy pulse. Ting Li Ku Jiu Tang (Lepidium Seed and Vinegar Decoction) is indicated.
[Chills After Sweating]
Chills appearing after sweating indicate that the exterior syndrome has not been completely resolved; this is a mild condition, and the method should be to induce sweating again. If yang qi is weak on the exterior and cold accumulates internally, leading to cold extremities and spontaneous diarrhea, Si Ni Tang (Frigid Extremities Decoction) is used. If yang qi is weak on the exterior and heat is concealed internally, with dry stool, purgation is employed. If the pulse does not slow down after sweating but becomes more rapid and restless than before, this is called "Yin-Yang Intersection" (Yin Yang Jiao), which indicates death. (This section should be read together with sections on failure to sweat and previous chills.)
[Releasing the Exterior]
For chills after sweating where the exterior remains unresolved, induce sweating with Ma Huang Tang (Ephedra Decoction).
[Resolving Both Interior and Exterior]
If fever persists after sweating, bowel movements are unobstructed, and there is only slight chills, first resolve the exterior, then use Da Chai Hu Tang (Major Bupleurum Decoction) or Xiao Cheng Qi Tang (Minor Order the Qi Decoction).
[Warming Method]
For weakness of yang and chills after sweating, with loose stools, Shao Yao Fu Zi Gan Cao Tang (Peony, Aconite, and Licorice Decoction) is indicated. For chills, spontaneous diarrhea, and cold extremities after sweating, Si Ni Tang (Frigid Extremities Decoction) is indicated.
[Failure to Cure After All Three Methods]
If the disease persists after using sweating, vomiting, and purging methods, it is due to excess or deficiency. If residual pathogenic factors are not exhausted, it must be a dual deficiency of yin and yang. At this time, careful deliberation is required: purge if appropriate, tonify if appropriate, so as not to cause death.
[Harmonizing Method]
On the fifth or sixth day, after sweating and purging, if there is fullness in the chest and hypochondrium, slight binding, difficulty in urination, thirst without vomiting, sweating only on the head, alternating chills and fever, and irritability, indicating the pathogen is not resolved, Chai Hu Gui Jiang Tang (Bupleurum, Ginger, and Trichosanthes Root Decoction) is indicated. After Taiyang disease is treated with sweating, vomiting, and purging, if there is hardness and oppression in the epigastrium and persistent belching, Xuan Fu Dai Zhe Shi Tang (Inula, Hematite, and Oyster Shell Decoction) is indicated.
[Resolving]
If Taiyang disease was first treated with sweating and failed, then purged, and the pulse is floating, knowing the pathogen is still external, the exterior should be resolved with Guizhi Tang (Cinnamon Twig Decoction).
[Cooling Method]
Seven or eight days after vomiting and purging, if the disease is unresolved, heat is bound internally, causing heat in both interior and exterior, occasional aversion to wind, extreme thirst, dry tongue with irritability and desire to drink water, Bai Hu Jia Ren Shen Tang (White Tiger Decoction plus Ginseng) is indicated.
[Warming Method]
If the disease remains unresolved after sweating and purging, with restlessness and insomnia, Fu Ling Si Ni Tang (Poria and Frigid Extremities Decoction) is indicated. For profuse sweating or severe diarrhea leading to cold extremities, Si Ni Tang (Frigid Extremities Decoction) is indicated.
After purgation followed by sweating, if there is irritability and insomnia during the day but quietness at night, without vomiting or thirst, no exterior signs, a deep and faint pulse, and no significant body heat, Gan Jiang Fu Zi Tang (Dried Ginger and Aconite Decoction) is indicated. After purgation followed by sweating, if the pulse is faint and fine with trembling from cold, this indicates dual deficiency of interior and exterior. After vomiting and purging, if food is vomited immediately upon entering the mouth, Gan Jiang Huang Lian Huang Qin Ren Shen Tang (Dried Ginger, Coptis, Scutellaria, and Ginseng Decoction) is indicated.
[Emetic Method]
After sweating, vomiting, and purging, if there is empty irritability and insomnia, or severe cases with tossing and turning and inner restlessness, Zhi Zi Chi Tang (Gardenia and Fermented Soybean Decoction) is indicated. After sweating or purging, if there is irritability, heat, and obstruction in the chest, Zhi Zi Chi Tang (Gardenia and Fermented Soybean Decoction) is indicated.
[Purgative Method]
After vomiting and purging, if there is constipation for five to six days up to ten-plus days, with tidal fever in the late afternoon, aversion to cold absent, delusions such as seeing ghosts, picking at clothes and bedrails, a wiry pulse indicates survival, while a choppy pulse indicates death. If there is only fever and delirium, Da Cheng Qi Tang (Major Order the Qi Decoction) is indicated. Abdominal distension after vomiting and purging indicates pathogenic heat entering the stomach; Tiao Wei Cheng Qi Tang (Regulate the Stomach and Order the Qi Decoction) is indicated. After Taiyang disease is treated with vomiting and purging, if there is slight irritability, frequent urination, and hard stool, Xiao Cheng Qi Tang (Minor Order the Qi Decoction) is indicated.
[Harmonizing Channels and Benefiting Yang]
After vomiting and purging, if there is reverse fullness in the epigastrium, qi rushing to the chest, dizziness, and a deep, tight pulse, inducing sweating will disturb the channels, causing body tremors and shaking. Fu Ling Gui Zhu Bai Zhu Gan Cao Tang (Poria, Cinnamon Twig, Atractylodes Macrocephala Rhizome, and Licorice Decoction) is indicated.