【纲】仲景曰。中风发热。六七日不解而烦。有表里症。渴欲饮水。水入则吐者。名曰水逆。
【目】朱肱曰。伤寒表症当汗。里症当下。不易之法也。发表攻里。本自不同。桂枝承气。安
可并进。然使病患脉浮而大。是表症当汗。其人发热烦渴。小便赤。即当下。此是表里俱见。五苓
散主之。若不大便六七日。头痛有热者。是里症。当下。其人小便清者。知不在里。仍在表也。当须
发汗。此是两症俱见。即未可下。宜与桂枝汤。若心下满。不欲食。大便硬。脉沉细。是里症当下。
其人头汗出。微恶寒。手足冷。即当汗。此两症俱见。仲景所谓半在表半在里也。小柴胡主之。
若太阳病。表症未除。医数下之。遂挟热而利不止。心下痞硬。仲景谓之表里不解。桂枝人参汤。
本太阳病。医反下之。因而腹痛。是有表复有里。仲景用桂枝芍药汤。痛甚者。桂枝加大黄。太阳
病桂枝症。医反下之。利遂不止。脉促者。表未解也。喘而汗出者。葛根黄芩汤。烦躁口苦。腹满
而喘。发热汗出。不恶寒。反恶热。此阳明症也。则脉反浮而紧。是表里俱见。不可汗下。宜栀子
豉汤吐之。此仲景治伤寒有表复有里之法也。
王好古曰。大柴胡汤。治表里内外俱热之症。治有表者。或脉浮。或头痛。或恶风。或恶寒。
四症中有一二尚在者。乃十三日过经不解是也。治有里者。或谵语。或妄见。或掷手扬视。此皆里之
急者也。若欲汗。则里症已急。欲下。则表症尚在。通用大柴胡汤。
[General Principle] Zhang Zhongjing stated: In Wind-Stroke (Zhongfeng) presenting with fever, if the condition persists for six or seven days without resolution and is accompanied by vexation, there are simultaneous exterior and interior syndromes. If the patient feels thirsty and desires to drink water, but vomits immediately after swallowing, this syndrome is named "Water Reversal" (Shui Ni).
[Detailed Discussion] Zhu Gong said: For Exterior syndromes in Cold Damage (Shanghan), sweating methods should be employed; for Interior syndromes, purgative methods should be used. This is an unchangeable principle. Releasing the exterior and attacking the interior are fundamentally different treatments. How can Guizhi Tang (Cinnamon Twig Decoction) and Chengqi Tang formulas (e.g., Da Chengqi Tang) be administered simultaneously? However, if the patient's pulse is floating and large, indicating an Exterior syndrome requiring sweating, and the patient presents with fever, vexation, thirst, and dark urine, it indicates a need for purgation. This represents simultaneous presentation of Exterior and Interior syndromes, which should be treated primarily with Wuling San (Five-Ingredient Poria Pill). If there has been no bowel movement for six or seven days, accompanied by headache and fever, this is an Interior syndrome requiring purgation; however, if the urine is clear, it indicates the pathogen is not in the Interior but remains in the Exterior, and sweating should be employed. This is a case where both symptoms are present, and purgation should not yet be attempted; instead, Guizhi Tang is appropriate. If there is fullness below the heart, aversion to food, hard stools, and a deep, fine pulse, this is an Interior syndrome requiring purgation; however, if the patient sweats only on the head, has slight aversion to cold, and cold hands and feet, sweating should be employed. This is also a case of simultaneous symptoms, what Zhang Zhongjing referred to as "half in the Exterior, half in the Interior," which should be treated with Xiaochaihu Tang (Minor Bupleurum Decoction). If Taiyang disease (Taiyang Bing) exists with unresolved Exterior symptoms, and the physician repeatedly uses purgatives, leading to persistent diarrhea with heat, and epigastric stiffness and fullness, Zhang Zhongjing calls this "Exterior and Interior unresolved." Guizhi Renshen Tang (Cinnamon Twig and Ginseng Decoction) should be used. Originally a Taiyang disease, if the physician erroneously uses purgatives, resulting in abdominal pain, this indicates the presence of both Exterior and Interior conditions. Zhang Zhongjing used Guizhi Shaoyao Tang (Cinnamon Twig and Peony Decoction); for severe pain, Guizhi Dahuang Tang (Cinnamon Twig and Rhubarb Decoction) is used. In Taiyang disease presenting with Guizhi syndrome, if the physician erroneously uses purgatives, leading to persistent diarrhea, a rapid pulse indicates the Exterior is not resolved; panting with sweating indicates Ge Gen Huangqin Tang (Kudzu Root and Scutellaria Decoction). If there is vexation, bitter taste in the mouth, abdominal fullness with panting, fever with sweating, aversion to cold is absent, and there is aversion to heat, this is a Yangming syndrome; however, if the pulse is floating and tight, it indicates simultaneous Exterior and Interior syndromes, where neither sweating nor purgation is suitable. Zhi Zi Chi Tang (Gardenia and Fermented Soybean Decoction) should be used to induce vomiting. This is Zhang Zhongjing's method for treating Cold Damage with simultaneous Exterior and Interior syndromes.
Wang Haogu said: Da Chaihu Tang (Major Bupleurum Decoction) treats syndromes where heat exists in both the Exterior and Interior, internally and externally. For cases with Exterior symptoms, such as a floating pulse, headache, aversion to wind, or aversion to cold, if one or two of these four symptoms persist, it indicates that after thirteen days, the disease has passed through the meridians but has not resolved. For cases with Interior symptoms, such as delirium, visual hallucinations, or throwing objects and staring upward, these are all urgent Interior conditions. If one wishes to sweat, the Interior condition is already critical; if one wishes to purge, the Exterior condition still exists. Da Chaihu Tang is generally used.