伤寒阴阳易之为病。其人身体重。少气。少腹里急。或引阴中拘挛。热上冲胸。头重不欲举。
眼中生花。膝胫拘急者。烧 散主之。
阴阳易者。男子大病新瘥。尚有余热。妇人与之交而得病。名曰阳易。或妇人大病新瘥。余热
未尽。男子与之交而得病者。名曰阴易。以阴阳相感。精气交通。热气从之而传易也。其人身体重
少气者。劳伤真气。而热胜之也。少腹里急。或引阴中拘挛。及膝胫拘急者。精虚热入。而脉道不
通也。热上冲胸。头重不欲举。眼中生花。则热气重蒸。而且上淆清阳矣。
大病瘥后劳复者。枳实栀子豉汤主之。若有宿食者。加大黄如博棋子大五六枚。
大病新瘥。血气未复。余热未尽。而强力作劳。因复发热者。名曰劳复。为其余热之气。因劳
而外浮也。枳实、栀子。所以下热。豆豉所以散热。盖亦表里之剂。而气味轻薄。适宜于病后复发
之体耳。若有宿食者。名曰食复。内经所谓食肉则复。多食则遗也。故于枳实栀子豉汤中少加大黄
。以逐其宿食。
枳实栀子豉汤方
枳实（三枚炙） 栀子（十四枚擘） 豉（一升绵裹）
上以清浆水七升。空煮取四升。纳枳栀。煮取二升。下豉。更煮五六沸。去滓。温分再服。覆
令微似汗。伤寒瘥已后更发热者。小柴胡汤主之。脉浮者。以汗解之。脉沉实者。以下解之。
伤寒瘥已后更发热者。不因作劳。亦未过食。而未尽之热自从内而达于外也。故与小柴胡汤。
因其势而解之。且人参、甘枣。可以益病后之虚。黄芩、半夏。可以和未平之里也。脉浮者。邪气
连表。汗之使之外解。脉沉实者。邪气居里。下之使从里解。亦因其势而利导之耳。
大病瘥后。从腰以下有水气者。牡蛎泽泻散主之。
大病新瘥。而腰以下肿满者。此必病中饮水过多。热邪虽解。水气不行。浸渍于下。而肌肉肿
满也。是当以急逐水邪为法。牡蛎泽泻散咸降之力居多。饮服方寸匕。不用汤药者。急药缓用。
且不使助水气也。若骤用补脾之法。恐脾气转滞而水气转盛。宁不泛滥为患耶。
牡蛎泽泻散方
牡蛎（熬） 泽泻 栝蒌根 葶苈（熬） 商陆根 蜀漆（洗去腥） 海藻（洗去咸各等分）
上七味。异捣下筛为散。更入臼中治之。白饮和服方寸匕。小便利。止后服。
大病瘥后。喜唾。久不了了者。胃上有寒。当以丸药温之。宜理中丸。
大病瘥后。胃阴虚者。津液不生。则口干欲饮。胃阳弱者。津液不摄。则口不渴而喜唾。至久
之而尚不了了。则必以补益其虚。以温益其阳矣。曰胃上有寒者。非必有客气也。虚则自生寒耳。
理中丸补虚温中之良剂。不用汤者。不欲以水气资吐也。
伤寒解后。虚羸少气。气逆欲吐者。竹叶石膏汤主之。
大邪虽解。元气未复。余邪未尽。气不足则因而生痰。热不除则因而上逆。是以虚羸少食。而
气逆欲吐也。竹叶石膏汤乃白虎汤之变法。以其少气。故加参、麦之甘以益气。以其气逆有饮。故
用半夏之辛以下气蠲饮。且去知母之咸寒。加竹叶之甘凉。尤于胃虚有热者为有当耳。
竹叶石膏汤方
竹叶（二把） 石膏（一斤） 人参（三两） 粳米（半升） 半夏（半升洗） 甘草（二两
炙） 麦冬（一升去心）
上七味。以水一斗。煮取六升。去滓。纳粳米。煮米熟汤成。去米。温服一升。日三服。
病患脉已解。而日暮微烦。以病新瘥。人强与谷。脾胃气尚弱。不能消谷。故令微烦。损谷则
愈。
脉已解者。病邪解而脉已和也。微烦、微热也。解则不当复烦。而日暮微烦者。以病新瘥。不
当与谷而强与之。胃虚谷实。不能胜之。则发烦热也。损谷则愈者。谓不可以药治之。但损其谷食
。则胃自和耳。
The disease known as "Yin-Yang Exchange" (Yin Yang Yi) following a Taiyang syndrome presents with the patient experiencing heavy body, shortness of breath (Shao Qi), urgency and tightness in the lower abdomen, sometimes extending to spasms in the genitalia, heat rushing up to the chest, heaviness of the head making it difficult to lift, visual disturbances such as seeing spots before the eyes, and stiffness and cramping of the knees and shins. This condition should be primarily treated with Shao Kun San (Burned Underwear Powder).
"Yin-Yang Exchange" refers to a situation where a man, newly recovered from a major illness but still harboring residual heat, contracts a disease through sexual intercourse with a woman; this is called "Yang Exchange." Conversely, if a woman, newly recovered from a major illness with lingering heat, contracts a disease through sexual intercourse with a man, it is called "Yin Exchange." This occurs due to the mutual influence of Yin and Yang, the communication of essence and qi, allowing the pathogenic heat to transmit accordingly. The heaviness of the body and shortness of breath result from labor injuring the true qi, which is then overcome by heat. The urgency in the lower abdomen, spasms in the genitalia, and stiffness of the knees and shins are caused by deficiency of essence and blood combined with the invasion of heat, leading to obstruction of the meridians. The heat rushing to the chest, head heaviness, and visual disturbances indicate severe steaming of heat that disturbs the clear yang qi ascending upwards.
For recurrence of symptoms due to overexertion after a major illness has healed, Zhi Shi Zhi Zi Chi Tang (Immature Bitter Orange, Gardenia, and Fermented Soybean Decoction) is the primary treatment. If there is retained food stagnation, add Da Huang (Rhei Radix et Rhizoma), sized like game pieces, five or six tablets.
When a major illness has just healed, blood and qi have not yet recovered, and residual heat remains, forcing physical labor may cause fever to return; this is termed "Labor Recurrence" (Lao Fu). This happens because the residual heat qi floats outward due to exertion. Zhi Shi (Immature Bitter Orange) and Zhi Zi (Gardenia Fruit) are used to purge heat, while Chi Xiao Dou (Fermented Soybean) dissipates heat. This is a formula acting on both exterior and interior, but with light aroma and flavor, suitable for bodies prone to recurrence after illness. If retained food is present, it is termed "Food Recurrence" (Shi Fu). As stated in the *Neijing* (Classic of Internal Medicine): "Recurrence occurs from eating meat, and lingering symptoms occur from overeating." Therefore, a small amount of Da Huang is added to Zhi Shi Zhi Zi Chi Tang to drive out the retained food.
Zhi Shi Zhi Zi Chi Tang Formula:
Zhi Shi (Immature Bitter Orange) - 3 pieces, roasted
Zhi Zi (Gardenia Fruit) - 14 pieces, broken open
Chi Xiao Dou (Fermented Soybean) - 1 sheng, wrapped in silk cloth
Take these three ingredients, boil in 7 sheng of Qing Jiang Shui (Clear Acidic Water) until reduced to 4 sheng. Add Zhi Shi and Zhi Zi, boil until reduced to 2 sheng. Then add Chi Xiao Dou, boil for 5-6 more boils. Strain. Take warm, divided into two doses. Cover with blankets to induce slight sweating.
If fever recurs after the resolution of Taiyang syndrome, Xiao Chai Hu Tang (Minor Bupleurum Decoction) is the primary treatment. If the pulse is floating, resolve via sweating (diaphoresis); if the pulse is deep and excess, resolve via purgation.
Fever recurring after Taiyang syndrome resolves, without being caused by overexertion or dietary indiscretion, indicates that residual heat naturally moves from the interior to the exterior. Thus, Xiao Chai Hu Tang is given to resolve the pathogen according to its trend. Furthermore, Ren Shen (Ginseng Root), Gan Cao (Licorice Root), and Da Zao (Jujube Fruit) tonify post-illness deficiency, while Huang Qin (Scutellaria Root) and Ban Xia (Pinellia Tuber) harmonize the unsettled interior. A floating pulse indicates pathogen affecting the exterior, resolved by sweating to expel it outward. A deep and excess pulse indicates pathogen residing in the interior, resolved by purgation to expel it inward. This is also guiding the pathogen according to its trend.
If edema and water retention occur below the waist after a major illness heals, Mu Li Ze Xie San (Oyster Shell and Alisma Powder) is the primary treatment.
Swelling and fullness below the waist shortly after a major illness often results from excessive water intake during the illness. Although the heat pathogen has resolved, water qi fails to circulate, soaking the lower parts and causing muscle swelling. The method here must be to urgently drain the water pathogen. Mu Li Ze Xie San relies heavily on salty and descending properties. Administer one fang cun bi (square-inch spoonful) of the powder. Decoctions are avoided to use urgent remedies slowly and to prevent adding to the water qi. Sudden use of spleen-tonifying methods might cause spleen qi to stagnate further and increase water accumulation, potentially leading to disastrous flooding.
Mu Li Ze Xie San Formula:
Mu Li (Oyster Shell), roasted
Ze Xie (Alisma Rhizome)
Gua Lou Gen (Trichosanthes Root)
Ting Li Zi (Descurainia Seed), roasted
Shang Lu Gen (Phytolacca Root)
Shu Qi (Patrinia Herb), washed to remove fishy odor
Hai Zao (Seaweed), washed to remove saltiness
(All ingredients in equal proportions)
Grind the seven ingredients separately into powder, sieve them, and grind again in a mortar. Mix with rice water and take one fang cun bi. Stop administration once urination becomes smooth.
After a major illness heals, if the patient frequently spits saliva and the condition persists for a long time without improvement, it is due to cold in the stomach. It should be treated with pill medicine to warm the interior, specifically Li Zhong Wan (Regulate the Middle Pill).
After a major illness heals, if yin deficiency of the stomach prevents fluid generation, dry mouth and thirst occur. If yang deficiency of the stomach fails to secure fluids, there is no thirst but frequent spitting. If this persists, deficiency must be tonified and yang warmed. The phrase "cold in the stomach" does not necessarily imply an external pathogenic factor, but rather cold generated internally due to deficiency. Li Zhong Wan is an excellent formula for tonifying deficiency and warming the middle. Pills are preferred over decoctions to avoid using water volume to exacerbate vomiting tendencies.
After the resolution of Taiyang syndrome, if the patient is emaciated and weak, suffers from shortness of breath, and experiences rebellious qi with a desire to vomit, Zhu Ye Shi Gao Tang (Bamboo Leaf and Gypsum Decoction) is the primary treatment.
Although the major pathogen has resolved, yuan qi has not recovered, and residual pathogens remain. Qi deficiency generates phlegm, and unremoved heat causes upward rebellion. Hence, emaciation, poor appetite, rebellious qi, and nausea occur. Zhu Ye Shi Gao Tang is a modification of Bai Hu Tang (White Tiger Decoction). Because of shortness of breath, Ren Shen (Ginseng Root) and Mai Dong (Ophiopogon Tuber) are added for their sweet nature to benefit qi. Because of rebellious qi and fluid retention, Ban Xia (Pinellia Tuber) is used for its acrid nature to direct qi downward and eliminate fluids. Zhi Mu (Anemarrhena Rhizome)'s salty-cold property is removed, and Zhu Ye (Bamboo Leaf)'s sweet-cool property is added, making it particularly suitable for stomach deficiency with heat.
Zhu Ye Shi Gao Tang Formula:
Zhu Ye (Bamboo Leaf) - 2 handfuls
Shi Gao (Gypsum Fibrosum) - 1 jin
Ren Shen (Ginseng Root) - 3 liang
Jing Mi (Rice) - 0.5 sheng
Ban Xia (Pinellia Tuber), washed - 0.5 sheng
Gan Cao (Licorice Root), roasted - 2 liang
Mai Dong (Ophiopogon Tuber), heart removed - 1 sheng
Boil the seven ingredients in 10 dou of water until reduced to 6 sheng. Strain. Add Jing Mi (Rice), cook until rice is done and liquid is ready. Remove rice. Take 1 sheng warm, three times daily.
If a patient's pulse has normalized but they experience mild vexation in the late afternoon, it is because the illness has just healed, people force-feed them, and the spleen and stomach qi are still weak, unable to digest the food, thus causing mild vexation. Reducing food intake will lead to recovery.
"Pulse normalized" means the pathogen has resolved and the pulse has harmonized. Mild vexation implies mild heat. Since it has resolved, vexation should not recur. Vexation in the late afternoon occurs because, upon recent healing, food was forced upon the patient despite the stomach being weak and unable to handle the load, triggering vexation and heat. "Reducing food intake leads to recovery" means medication is unnecessary; simply reducing grain and food intake allows the stomach qi to harmonize itself.