阳厥，脉沉而有力，腹痛后重，大便稠粘，小便赤涩，或大便不通，必是先热
后发厥也。其四肢虽冷，上不过肘，下不过膝，此热深阳厥也，承气汤下之。
阴厥，脉沉而无力，口不渴，四肢痛甚，及大便泄利，小便清白，而身怕寒，面如刀刮，四肢
厥冷，上过乎肘，下过乎膝，此阴厥也，四逆汤治之。两阳交尽，名曰厥阴也。大抵三阴无传经，
胃实热可下也。又有伤寒两感者，病为巨阳老阴也。
大抵伤寒先须识证，察得阴阳表里、虚实寒热亲切，更审汗、吐、下、温、和解之法治之，庶
无差误。先看两目，次看口舌，后以手按其心胸至小腹有无痛满用药。如目皆黄，必为欲愈之病也。
眼胞忽陷，目睛直视，必难治也。开目欲见人，属阳，闭目不欲见人，属阴。目睛不明，神水已竭，
不能照物者，亦难治也。
次看口舌，上有白苔者，为热。见黄苔者，为热甚。见黑苔及生芒刺者，必死。
后按其心胸，有痛而满闷者，亦未经下之，为表邪尚在少阳部分，只用小柴胡汤加枳壳、桔梗
为的。如按其心下满痛甚者，已经下矣，为结胸，正用陷胸汤，看微甚而用之。陷胸宜从缓治。结
胸证，烦躁悉具者，死也。
如小腹觉有硬痛，当按其痛处，更问其小便通利若何。如通，则知蓄血下焦，宜破瘀血，用桃
仁承气汤，下尽黑物为好。如小便不通，则知津液留结，宜五苓散加木通、山栀治之。
但觉发热恶寒，头痛，腰脊强，脉浮，不拘日数，即是太阳表证。浮紧有力，无汗，为伤寒，
宜发汗；浮缓无力，有汗，为伤风，宜实表。
但见肢痛，咽干而渴，身无热，手足温，脉沉有力，明是热邪传来太阴里证，宜当下之。如肢
痛，自利不渴，恶寒，手足厥冷，脉沉无力，此是太阴自受寒也，宜当温之。
但见口燥咽干而渴，妄语怕热，大便闭，或微利清水而大渴，脉沉有力，明是热邪传来少阴里
证，不拘日数，即宜下之。如肢痛，泄利呕吐，怕寒，手足厥冷，不渴，脉沉无力，此是少阴直中
自受，内寒阴证，急用温之。
但见舌卷囊缩而渴，身不热，外虽四肢厥冷，内有实热，脉来沉缓有力，或大便闭实，明是热
邪传来厥阴之证，即宜下之。如肢痛，泄利呕吐，不渴，怕寒，四肢厥冷，小便清利，脉微无力，
此是厥阴自中，其寒证也，急宜温之。俱照前六经中用药。
其一切燥渴，大便闭，发狂谵语，腹满微厥，斑血证，脉来有力者，俱是从三阳邪热传入三阴
里证，宜当下之，轻重用药无疑。如寒，当急温之，不可缓也。有伤寒一日传二经，为两感，三日
传尽，必死；再传，止于六日。夫两感发于表者，麻黄葛根汤也；攻里者，调胃承气汤也。如未尽
善，须问病者有无痛处。大小便通利，若胸痛者，为结胸；不痛者，为痞气，乃因下早而成也。未
经下者，非结胸也。乃表邪传至胸中，证虽满闷，尚有表邪，未及乎腑，正属少阳部分，用小柴胡
汤加枳壳以治之。如未效，以本方加小陷胸汤，服之而愈。痛甚者，大陷胸汤下之。
阳厥，脉象沉而有力，腹痛且伴有肛门坠胀感，大便稠粘，小便赤涩，或者大便不通，必定是先发热随后出现四肢厥冷。其四肢虽然寒冷，但冷不过肘部，冷不过膝部，这是热邪深伏导致的阳厥，应用承气汤攻下。
阴厥，脉象沉而无力，口不渴，四肢疼痛剧烈，以及大便泄泻，小便清亮色白，身体畏寒，面色惨白如刀刮过一般，四肢厥冷超过肘部和膝部，这是阴厥，应用四逆汤治疗。两阳经之气交尽，称为厥阴。大抵三阴病没有传经的情况，若胃中有实热可以攻下。又有伤寒两感证，病在巨阳（太阳）和老阴（少阴）。
大抵治疗伤寒必须先识别证候，仔细辨别阴阳、表里、虚实、寒热，再审慎运用汗、吐、下、温、和解等治法来治疗，这样才不会有差错。先看两眼，次看口舌，然后用手按压从心胸到小腹部位，询问是否有疼痛胀满以决定用药。如果双目发黄，必定是即将痊愈的病证。眼睑突然凹陷，眼球直视不动，必定难以治疗。睁眼想见人，属于阳证；闭眼不想见人，属于阴证。眼睛视物不明，神水已枯竭，不能映照外物的，也难以治疗。
其次看口舌，舌上有白苔的，为热证。见黄苔的，为热甚。见黑苔及生芒刺的，必定死亡。
然后按压心胸部位，若有疼痛且胀闷的，也未曾使用过攻下法，说明表邪仍在少阳部分，只用小柴胡汤加枳壳、桔梗作为对症之方。如果按压心下部位胀满疼痛剧烈的，已经使用过攻下法，这是结胸证，正用陷胸汤，根据病情轻重而使用。陷胸证宜从缓治疗。结胸证，如果烦躁症状全部具备的，预后不良致死。
如果小腹部感觉有硬痛，应当按压疼痛处，再询问其小便通利情况如何。如果小便通利，则知道是瘀血蓄积在下焦，宜破瘀血，用桃仁承气汤，排出黑色粪便为好。如果小便不通，则知道是津液留结，宜用五苓散加木通、山栀治疗。
只要觉得发热恶寒，头痛，腰脊僵硬，脉浮，不拘泥于患病天数，即是太阳表证。脉浮紧有力，无汗，为伤寒，宜发汗；脉浮缓无力，有汗，为伤风，宜固护肌表。
只要见到肢体疼痛，咽干而渴，身体无热，手足温暖，脉沉有力，明显是热邪传入太阴里的证候，宜当下之。如果肢体疼痛，自发性腹泻且不渴，恶寒，手足厥冷，脉沉无力，这是太阴直接感受寒邪，宜当温之。
只要见到口燥咽干而渴，胡言乱语怕热，大便闭塞，或者微利清水而极度口渴，脉沉有力，明显是热邪传入少阴里的证候，不拘泥于患病天数，即宜攻下。如果肢体疼痛，泄泻呕吐，怕寒，手足厥冷，不渴，脉沉无力，这是少阴直中自受，内寒阴证，急用温之。
只要见到舌头卷缩、阴囊收缩而渴，身体不热，外部虽然四肢厥冷，内部却有实热，脉来沉缓有力，或者大便闭塞坚实，明显是热邪传入厥阴的证候，即宜攻下。如果肢体疼痛，泄泻呕吐，不渴，怕寒，四肢厥冷，小便清利，脉微无力，这是厥阴直中，属于寒证，急宜温之。都参照前面六经中的用药原则。
其一切燥渴，大便闭塞，发狂谵语，腹满微厥，斑疹出血证，脉来有力的，都是从三阳邪热传入三阴里证，宜当下之，用药轻重无疑。如果是寒证，当急温之，不可迟缓。有伤寒一日传入两经，称为两感，三日传遍六经，必死；如果再传，止于第六日。凡两感证发于表的，用麻黄葛根汤；攻里的，用调胃承气汤。如果治疗未尽完善，须询问病人是否有疼痛之处。大小便通利，如果胸痛者，为结胸；不痛者，为痞气，乃因过早攻下而成。未经攻下的，不是结胸。乃是表邪传至胸中，证候虽满闷，尚有表邪，未及入腑，正属少阳部分，用小柴胡汤加枳壳以治疗。如果无效，用本方加小陷胸汤，服用后痊愈。疼痛剧烈的，用大陷胸汤攻下。
Yang Jue (Cold Extremities due to Heat), the pulse is deep and forceful, abdominal pain with a sensation of heaviness in the anus, thick and sticky stool, red and scanty urine, or constipation; this indicates that heat occurred first followed by cold extremities. Although the four limbs are cold, the cold does not extend beyond the elbows or knees; this is Yang Jue caused by deep-seated heat, treated with Chengqi Tang (Cathartic Decoction) to purge.
Yin Jue (Cold Extremities due to Cold), the pulse is deep and weak, no thirst, severe pain in the four limbs, diarrhea, clear and colorless urine, aversion to cold, face pale as if scraped by a knife, cold extremities extending beyond the elbows and knees; this is Yin Jue, treated with Sini Tang (Frigid Extremities Decoction). When the two Yang meridians reach their end, it is called Jueyin (Terminal Yin). Generally, the Three Yin meridians do not transmit disease via the meridian sequence; if there is excess heat in the stomach, purgation is indicated. There is also the condition of "Shanghan Lianggan" (Simultaneous contraction of Taiyang and Shaoyin in Cold Damage), where the disease affects Juyang (Taiyang/Bladder) and Laoyin (Shaoyin/Kidney).
Generally, treating Shanghan requires first identifying the syndrome, carefully distinguishing Yin/Yang, Exterior/Interior, Deficiency/Excess, and Cold/Heat, then prudently applying methods such as sweating, vomiting, purging, warming, and harmonizing to avoid errors. First observe the eyes, then the mouth and tongue, then palpate from the chest/heart down to the lower abdomen for pain or fullness to guide medication. If both eyes are yellow, it indicates the disease is about to resolve. If the eyelids suddenly sink and the eyeballs stare fixedly, it is difficult to treat. Opening the eyes and wanting to see people belongs to Yang; closing the eyes and not wanting to see people belongs to Yin. If vision is unclear, the Shen Shui (Spirit Water/Clear Humor) is exhausted, unable to reflect objects, which is also difficult to treat.
Next, examine the mouth and tongue: white coating indicates heat; yellow coating indicates intense heat; black coating with prickles indicates death.
Then palpate the chest and heart: if painful and distended, and purgatives have not yet been used, the exterior pathogen remains in the Shaoyang portion; use Xiaochaihu Tang (Minor Bupleurum Decoction) with Zhike (Aurantii Fructus Immaturus) and Jiegeng (Platycodonis Radix) as the specific formula. If pressing the epigastrium causes severe fullness and pain, and purgatives have already been used, this is Jie Xiong (Chest Binding), treated with Xiantong Tang (Resolving Chest Binding Decoction), adjusted according to severity. Xiantong should be treated cautiously. If Jie Xiong presents with complete irritability, it is fatal.
If the lower abdomen feels hard and painful, press the tender area and ask about urination. If urination is free, it indicates blood stasis in the Lower Jiao; promote blood breaking using Tao Ren Chengqi Tang (Peach Kernel Cathartic Decoction) until dark stools are passed. If urination is obstructed, it indicates fluid retention; use Wuling San (Five-Ingredient Powder with Poria) plus Mutong (Akebiae Caulis) and Shanzhi (Gardeniae Fructus).
If fever, aversion to cold, headache, stiff neck/spine, and floating pulse appear, regardless of the number of days, it is a Taiyang Exterior Syndrome. Floating and tight pulse without sweat indicates Shanghan (Cold Damage); induce sweating. Floating and slow pulse without force with sweat indicates Shangfeng (Wind Strike); secure the exterior.
If limb pain, dry throat with thirst, no body heat, warm hands/feet, and deep forceful pulse appear, it is clearly a Taiyin Interior Syndrome transmitted by heat; purgation is indicated. If limb pain, spontaneous diarrhea without thirst, aversion to cold, cold extremities, and deep weak pulse appear, it is Taiyin directly contracting cold; warming is indicated.
If dry mouth/throat with thirst, delirium, aversion to heat, constipation, or slight passage of clear water with extreme thirst, and deep forceful pulse appear, it is clearly a Shaoyin Interior Syndrome transmitted by heat; purgation is indicated regardless of days. If limb pain, diarrhea/vomiting, aversion to cold, cold extremities, no thirst, and deep weak pulse appear, it is Shaoyin direct invasion, an interior cold Yin syndrome; urgent warming is indicated.
If tongue curling, scrotal retraction, thirst, no body heat, external cold extremities but internal excess heat, and deep slow forceful pulse or constipation appear, it is clearly a Jueyin syndrome transmitted by heat; purgation is indicated. If limb pain, diarrhea/vomiting, no thirst, aversion to cold, cold extremities, clear urine, and faint weak pulse appear, it is Jueyin direct invasion, a cold syndrome; urgent warming is indicated. Follow the medication principles of the Six Meridians described earlier.
All cases of dry thirst, constipation, mania/delirium, abdominal fullness with mild cold extremities, macules/hemorrhage, and forceful pulses are due to heat pathogens from the Three Yang transmitting to the Three Yin interior; purgation is indicated, adjusting dosage strength accordingly. For cold, urgent warming is required. If Shanghan transmits to two meridians on day one, it is Lianggan; if it transmits through all six meridians by day three, death ensues; further transmission stops at day six. For Lianggan manifesting on the exterior, use Mahuang Gegen Tang (Ephedra and Kudzu Decoction); for interior attack, use Tiaowei Chengqi Tang (Regulating the Stomach Cathartic Decoction). If treatment is incomplete, ask if the patient has pain. With free bowel/bladder movement, chest pain indicates Jie Xiong; absence of pain indicates Pi Qi (Stagnant Qi), caused by premature purgation. Without prior purgation, it is not Jie Xiong. It is exterior pathogen transmitting to the chest; although full/distended, exterior pathogen remains, not yet entering the Fu organs, belonging to Shaoyang; treat with Xiaochaihu Tang plus Zhike. If ineffective, add Xiao Xiantong Tang (Minor Resolving Chest Binding Decoction) to the base formula until cured. For severe pain, use Da Xiantong Tang (Major Resolving Chest Binding Decoction) to purge.