伤寒表里轻重，验舌色亦得大半。杜青碧有三十六法，反觉太繁。今余分立白苔、黑苔、黄
苔、燥苔、滑苔、五者以为要。舌色如常，身虽大热，是表热里未有热也，但治其表。如
见白苔而滑，邪在半表半里、未入于里也，但宜和解。若见黄苔者，热在胃家；苔黄而干裂
者，热已入里，宜清里热。若有下症者，可以下之。若见黑苔者，有二条分别∶黑而焦裂硬
刺者，里热已极，火极似炭之苔也；黑而有水、软润而滑者，里寒已甚，水来克火之寒苔
也。以上五者，验舌之大节目也，然仍要看症切脉以参定之。如舌上黑苔，燥裂有刺，此里
热无疑矣，然或身痛，或足冷，或无汗，或脉浮，或脉伏，仍从表症治之。虽不可用辛温之
药，必宜辛凉散表，然后清里。若过用清热，则表汗不出，表邪不解。又如舌上生苔，口渴
不能消水，脉浮大不数，服清热之药，反加谵妄神昏，此症多见不治。以舌苔主里热，渴宜
消水，脉宜沉数，数症脉相反故耳。然余以渴不消水，脉滑不数，拟以食滞，用消导治之，
亦有生者。自此则知表邪夹食之症，亦有舌苔生刺者也。大凡察病患之舌，沿边缺陷如锯齿
口者，此不治之症也。
伤寒验口中干湿，可以定其症之表里轻重，然验口更当验唇。口唇关手足阳明肠胃二经，又
关手足太阴脾肺二脏。故验唇色红润，里未有热，但宜辛温散表。唇色干枯，里已有热，宜
清里。唇色焦黑，烦渴消水，里热已极，当用凉膈散等。又有谵语发狂，唇色干焦，服寒凉
而热不减，此食滞中焦，胃中蕴蓄，发黄发热。是以用凉药。则食滞不消，用辛散则碍里
热，宜以保和散冲竹沥、芦卜汁，或栀子豆豉汤加陈枳实治之。上唇属肺与大肠，上唇焦
而消渴饮水，热在上，主肺；上唇焦而不消渴饮水，热在下，主大肠有燥粪。下唇属脾与
胃，下唇焦而消渴饮水，热在阳明胃；下唇焦而不消渴饮水，热在太阴脾。余今发明里热唇
焦，食滞唇焦，积热伏于血分而唇焦，惟以渴不渴、消水不消水分别。然食滞唇焦，又有食
滞已久，蒸酿发热，亦能作渴消水，又当参脉象若何。脉若滑大不数，食未蒸热，口亦不
渴；若滑大沉数，食已发热，口亦作渴。故凡谵语发狂；脉滑不数，渴不消水者，亦以食滞
治之；若以寒凉抑遏，则谵语发狂愈甚，甚则口噤不语也。
伤寒病表证与里证的轻重程度，通过观察舌色也能判断出大部分情况。杜青碧提出的三十六种舌诊方法，反而觉得过于繁杂。如今我单独列出白苔、黑苔、黄苔、燥苔、滑苔这五种作为要点。如果舌色如常，身体虽然高热，这是表热而里无热，只需治疗表证。如果见到白苔且滑润，说明邪气在半表半里，尚未入里，适宜采用和解法。如果见到黄苔，说明热在胃家；若苔黄且干燥开裂，说明热已入里，应当清泄里热。如果有可下之症，可以使用攻下法。如果见到黑苔，有两种情况需要区分：黑而焦裂、坚硬有刺的，是里热极盛，像火极似炭一样的舌苔；黑而有水气、柔软湿润滑利的，是里寒极甚，像水来克火一样的寒性舌苔。以上五种，是验舌的主要纲领，但仍然要结合症状和切脉来综合判定。例如舌上黑苔，干燥开裂且有刺，这无疑是里热，但如果伴有身痛、脚冷、无汗、脉浮或脉伏等症状，仍应从表证治疗。虽然不能用辛温药物，但必须用辛凉药物疏散表邪，然后才能清泄里热。如果过度使用清热药，会导致表汗不出，表邪不解。又比如舌上生苔，口渴但不能饮水（或饮水后不适），脉象浮大但不数，服用清热药后，反而出现谵语妄言、神志昏迷的症状，这种病症多见不治。因为舌苔主里热，口渴应能消水，脉象宜沉数，现在症状与脉象相反的缘故。然而我认为，如果是口渴不能消水，脉滑而不数，推测为食积停滞，用消导法治疗，也有治愈的。由此可知，表邪夹带食积的病症，也会有舌苔生刺的情况。大凡观察病人的舌头，边缘缺损如锯齿口的，这是不治之症。
伤寒病检查口中干湿，可以确定病症的表里轻重，然而检查口腔更应当检查嘴唇。口唇关联手足阳明经（大肠经、胃经）以及手足太阴脏（脾脏、肺脏）。所以观察唇色红润，说明里无热，只宜用辛温药物发散表邪。唇色干枯，说明里已有热，宜清泄里热。唇色焦黑，烦躁口渴且能大量饮水，说明里热极盛，应当使用凉膈散等方剂。又有出现谵语发狂，唇色干焦，服用寒凉药而热势不减的，这是食积停滞在中焦，胃中蕴蓄，导致发黄发热。因此使用凉药，则食积不消；用辛散药，则会妨碍里热的清除，适宜用保和散冲服竹沥、萝卜汁，或者用栀子豉汤加陈枳实治疗。上唇属于肺与大肠，上唇焦黑且口渴饮水，说明热在上部，主要责之于肺；上唇焦黑但不口渴饮水，说明热在下部，主要责之于大肠有燥屎。下唇属于脾与胃，下唇焦黑且口渴饮水，说明热在阳明胃；下唇焦黑但不口渴饮水，说明热在太阴脾。我现在阐明里热导致的唇焦、食滞导致的唇焦、积热伏于血分导致的唇焦，仅以是否口渴、能否消水来分别。然而食滞导致的唇焦，又有食积已久，蒸酿发热，也能作渴消水，这时又应当参考脉象如何。脉象如果滑大但不数，说明食积未蒸热，口也不渴；如果脉象滑大沉数，说明食积已发热，口也会作渴。所以凡是出现谵语发狂，脉滑不数，口渴但不能消水的，也以食积论治；如果用寒凉药抑制遏制，则谵语发狂会更加严重，甚至发展到口噤不语的地步。
The severity of exterior and interior syndromes in Shanghan (Cold Damage) can be largely determined by inspecting the tongue coating. Du Qingbi's thirty-six methods are considered overly complicated. I hereby establish five key categories: white coating, black coating, yellow coating, dry coating, and slippery coating. If the tongue color is normal despite high fever, it indicates exterior heat without interior heat; treatment should focus on the exterior. If a white and slippery coating is observed, the pathogen is at the half-exterior half-interior level and has not entered the interior; harmonization is appropriate. If a yellow coating is seen, heat resides in the Stomach organ system (Wei Jia); if the yellow coating is dry and cracked, heat has entered the interior, requiring clearing of interior heat. If there are indications for purgation, purgative methods may be used. Regarding black coatings, two distinct types must be differentiated: a black, scorched, cracked, hard, and prickly coating indicates extreme interior heat, resembling charcoal from excessive fire; a black coating with moisture, soft, moist, and slippery indicates severe interior cold, resembling water overcoming fire. These five types constitute the main principles of tongue diagnosis, yet symptoms and pulse palpation must still be consulted for confirmation. For instance, although a black, dry, cracked, and prickly coating undoubtedly indicates interior heat, if accompanied by body pain, cold feet, absence of sweating, floating pulse, or hidden pulse, treatment should still address the exterior syndrome. Although acrid-warm herbs are contraindicated, acrid-cool herbs should be used to disperse the exterior before clearing the interior. Overuse of heat-clearing herbs will prevent sweating and fail to resolve the exterior pathogen. Furthermore, if a patient has a coated tongue, thirst but inability to swallow water, and a floating, large, but non-rapid pulse, administering heat-clearing herbs may worsen the condition, leading to delirium and coma. This is often incurable because while tongue coating indicates interior heat and thirst suggests fluid consumption, the pulse should typically be deep and rapid; the contradiction between symptoms and pulse is the cause. However, I propose that if thirst is present but water is not swallowed, and the pulse is slippery and non-rapid, this suggests food stagnation, which can be treated with digestion-promoting methods, sometimes resulting in recovery. Thus, exterior syndromes complicated by food stagnation can also present with prickly tongue coatings. Generally, if the edges of the tongue show defects resembling sawteeth, it indicates an incurable condition.
Inspecting the mouth for dryness or moisture helps determine the exterior-interior severity of Shanghan, but lip inspection is equally important. The lips connect to the Hand and Foot Yangming meridians (Large Intestine and Stomach) and the Hand and Foot Taiyin organs (Spleen and Lung). Therefore, red and lustrous lips indicate no interior heat, suitable for acrid-warm exterior-dispersing treatments. Dry and withered lips indicate existing interior heat, requiring interior clearing. Scorched-black lips with irritability, thirst, and ability to drink water indicate extreme interior heat, warranting formulas such as Liangge San (Cool the Upper Burner Powder). In cases of delirium and mania with dry, scorched lips where cold-natured herbs fail to reduce fever, this indicates food stagnation in the Middle Jiao causing jaundice and fever. Cold herbs fail to resolve stagnation, while acrid dispersants hinder interior heat clearance; thus, Baohe San mixed with Zhuli (Bamboo Sap) and Lubo juice (Radish Juice), or Zhizi Chihui Tang (Gardenia and Fermented Soybean Decoction) plus Chen Zhishi (Aged Immature Bitter Orange) are appropriate. The upper lip corresponds to the Lung and Large Intestine; scorched upper lip with thirst and drinking indicates heat in the upper jiao, primarily affecting the Lung; scorched upper lip without thirst indicates heat in the lower jiao, primarily due to dry feces in the Large Intestine. The lower lip corresponds to the Spleen and Stomach; scorched lower lip with thirst and drinking indicates heat in the Yangming Stomach; scorched lower lip without thirst indicates heat in the Taiyin Spleen. I clarify that whether lip scorching results from interior heat, food stagnation, or latent heat in the blood level is distinguished by thirst and water consumption. However, long-standing food stagnation can generate heat through fermentation, causing thirst and water consumption, necessitating pulse differentiation. A slippery, large, non-rapid pulse indicates unfermented stagnation with no thirst; a slippery, large, deep, and rapid pulse indicates fermented heat with thirst. Therefore, delirium and mania with a slippery, non-rapid pulse, and thirst without water consumption, are treated as food stagnation. Using cold-natured herbs to suppress this will exacerbate delirium and mania, potentially leading to lockjaw and muteness.