头痛骨痛，身热恶寒属太阳，宜发散表邪；按其胸腹胀满，兼消导食积。如口燥鼻干，目痛，
不眠属阳明，宜解肌；胸宽而大便秘，宜攻下；如寒热口苦，胁痛耳聋属少阳，宜和解。如前一经
之证未罢，又见一经之证，名 病；如见两经之证，名二阳合病。如手足冷、脉沉，乃阴证也，尤
宜验舌色。伤寒切要分别表里、阴阳、寒热、虚实八字，生死系焉。舌色红润属表，属阴，属寒，
属虚；舌干有苔属里，属阳，属热，属实。如舌青紫，阴寒也；泥色，虚极也。舌干白苔，邪初入
里也！黄苔热甚；黑苔如芒
刺或卷缩，极热也。凡面赤病炽，面目黄色，病已。舌无苔，结成干赤光皮，似煨熟猪肾，乃阳中
伏阴也。舌苔黑而湿滑者，脏结证也。舌苔黄燥，足冷脉沉，亦非纯阳证，切忌硝、黄。
伤寒之脉，浮、大、动、滑、数属阳；沉、涩、弱、弦、微属阴。阴证见阳脉者生，阳证见阴
脉者死。外感、内伤之脉最宜察，人迎紧盛受风寒，气口紧盛伤饮食。初病脉浮紧有力，为伤寒；
初病脉浮缓无力，为伤风。有不浮者，一手无脉曰单伏；有不浮者，两手无脉曰双伏。略有头疼发
热，表证悉具，即当主方发汗，乃证书不凭脉也。有热邪传里，脉必沉，沉滑有力为里实，沉滑无
力为里虚。间有脉沉微无力者，但口渴便秘，身大热，手足温，实热证悉具，亦当大柴胡汤微下也
。阴证脉沉迟，微细无力，为虚，为寒，为脏病，宜甘温补益或辛热温散。阳证脉浮洪、实数有力
，为实、为热，为胃腑病，宜甘寒清解或苦寒下泄。虚证脉浮芤，细数无力，为表虚，宜参、 、
桂、芍以实表；沉涩微弱无力，为里寒，宜参、术、姜、桂、附子温里。实证脉洪大、滑数有力，
如斑狂谵语之证，为在经，宜三黄石膏汤或白虎汤清利。若便秘，舌苔之证为在腑，宜服大柴胡汤
或承气汤攻下。
头痛、骨痛，身体发热且怕冷，属于太阳病（太阳经受邪所致的病证），适宜使用发散表邪的方法；如果按压胸部和腹部感到胀满，兼有饮食积滞，需配合消食导滞。如果出现口燥、鼻干、目痛、失眠，属于阳明病（阳明经受邪所致的病证），适宜使用解肌法；如果胸胁宽舒但大便秘结，适宜使用攻下法。如果出现寒热往来、口苦、胁痛、耳聋，属于少阳病（少阳经受邪所致的病证），适宜使用和解法。
如果前一经的病证尚未消除，又出现了另一经的病证，称为“合病”；如果同时出现两经的病证，称为“二阳合病”。如果出现手足冰冷、脉象沉细，这是阴证，尤其需要查验舌色。伤寒的关键在于区分表、里、阴、阳、寒、热、虚、实这八个字，生死存亡系于此。舌色红润属于表证、阴证、寒证、虚证；舌干且有苔属于里证、阳证、热证、实证。如果舌色青紫，是阴寒之证；舌色如泥，是极度虚弱之证。舌干白苔，说明邪气刚入里；黄苔表示热势严重；黑苔如芒刺或卷缩，表示极热。凡是面色红赤、病势炽盛，或者面目发黄，病情已危重。舌面无苔，结成干燥赤红的皮状，像煨熟的猪肾，这是阳中伏阴之证。舌苔黑而湿滑的，是脏结证。舌苔黄燥，足冷脉沉，也不是纯阳证，切忌使用芒硝、大黄。
伤寒的脉象，浮、大、动、滑、数属于阳脉；沉、涩、弱、弦、微属于阴脉。阴证见到阳脉者生，阳证见到阴脉者死。外感和内伤的脉象最宜仔细察辨，人迎脉紧盛是受风寒所致，气口脉紧盛是伤于饮食所致。初病时脉象浮紧有力，为伤寒；初病时脉象浮缓无力，为伤风。也有不浮的脉象，一只手无脉称为单伏；两只手都无脉称为双伏。如果有轻微的头疼发热，表证全部具备，就应当以发汗为主方，这是证候不依赖脉象判断的情况。如果有热邪传入体内，脉象必然沉，沉滑有力为里实证，沉滑无力为里虚证。间或有脉象沉微无力的，但只要口渴、便秘、身体大热、手足温暖，实热证的征象全部具备，也应当用大柴胡汤轻微攻下。阴证的脉象沉迟、微细无力，属于虚证、寒证、脏腑病变，适宜用甘温补益或辛热温散的方法。阳证的脉象浮洪、实数有力，属于实证、热证、胃腑病变，适宜用甘寒清解或苦寒下泄的方法。虚证的脉象浮芤、细数无力，属于表虚证，适宜用人参、[缺字]、桂枝、芍药来固表；脉象沉涩微弱无力，属于里寒证，适宜用人参、白术、干姜、桂枝、附子来温里。实证的脉象洪大、滑数有力，如斑疹、狂乱、谵语等证候，病在经络，适宜用三黄石膏汤或白虎汤清热利湿。如果大便秘结、舌苔异常，病在腑，适宜服用大柴胡汤或承气汤攻下。
Headache, bone pain, fever with aversion to cold belong to Taiyang disease (disease of the Taiyang channel), suitable for dispersing exterior pathogens; palpation revealing chest and abdominal fullness accompanied by food stagnation requires digestion-promoting methods. Dry mouth, dry nose, eye pain, and insomnia belong to Yangming disease (disease of the Yangming channel), suitable for resolving the muscle layer; if the chest is comfortable but constipation exists, purgative methods are indicated. Alternating chills and fever, bitter taste in the mouth, hypochondriac pain, and deafness belong to Shaoyang disease (disease of the Shaoyang channel), suitable for harmonizing.
If the syndrome of one stage has not resolved and symptoms of another stage appear, it is called "He Bing" (Combined Disease); if symptoms of two stages appear simultaneously, it is called "Er Yang He Bing" (Combined Disease of Two Yang Stages). Cold hands and feet with a deep pulse indicate Yin syndrome, where tongue color should be carefully examined. The key to treating Shanghan (Cold Damage) lies in distinguishing eight principles: Exterior, Interior, Yin, Yang, Cold, Heat, Deficiency, and Excess, which determine life or death. A red and moist tongue indicates Exterior, Yin, Cold, or Deficiency syndromes; a dry tongue with coating indicates Interior, Yang, Heat, or Excess syndromes. A bluish-purple tongue indicates Yin-Cold; a muddy tongue color indicates extreme deficiency. A dry tongue with white coating indicates pathogenic factors just entering the Interior; yellow coating indicates severe heat; black coating like thorns or curled indicates extreme heat. Red face with intense illness or yellow complexion indicates critical condition. Tongue without coating forming a dry, red, shiny skin resembling roasted pig kidney indicates Yin hiding within Yang. Black and slippery tongue coating indicates Zang-Jie syndrome (accumulation in Zang organs). Yellow and dry tongue coating with cold feet and deep pulse does not indicate pure Yang syndrome; Magnoliae Officinalis Cortex (Huangbo, 黄柏) and Rheum Palmatum (Dahuang, 大黄) must be strictly avoided.
In Shanghan, floating, large, moving, slippery, and rapid pulses belong to Yang; deep, choppy, weak, wiry, and minute pulses belong to Yin. Survival is predicted when Yin syndrome presents with Yang pulse; death is predicted when Yang syndrome presents with Yin pulse. Pulses of external contraction and internal injury require careful differentiation. Tightness and excess at the Renying point (ST9, Renying) indicate wind-cold invasion; tightness and excess at the Qikou point (LU9, Taibai) indicate dietary injury. Initial floating and tight pulse with strength indicates Shanghan; initial floating and slow pulse without strength indicates Shangfeng (Wind Injury). Some pulses do not float: absence of pulse in one hand is called Dan Fu (Single Hidden Pulse); absence in both hands is called Shuang Fu (Double Hidden Pulse). If mild headache and fever occur with complete exterior symptoms, diaphoretic formulas should be primary; this is a case where syndrome determines treatment rather than pulse. When heat pathogen transmits inward, the pulse becomes deep; deep and slippery with strength indicates Interior Excess; deep and slippery without strength indicates Interior Deficiency. Occasionally, a deep, minute, and weak pulse appears, yet thirst, constipation, high fever, and warm extremities present fully as Excess-Heat syndrome; in such cases, Chaihu Daizhu Tang (Bupleurum and Rhubarb Decoction) should be used mildly to purge. Deep, slow, minute, and weak pulses in Yin syndrome indicate Deficiency, Cold, and Zang organ disease, suitable for sweet-warm tonification or pungent-hot warming dispersion. Floating, surging, excess, and rapid pulses with strength in Yang syndrome indicate Excess, Heat, and Stomach fu organ disease, suitable for sweet-cool clearing or bitter-cold purging. Floating, hollow, fine, and rapid pulses without strength in Deficiency syndrome indicate Exterior Deficiency, suitable for Ginseng Radix (Renshen, 人参), [missing character], Cinnamomi Ramulus (Guizhi, 桂枝), and Paeoniae Radix Alba (Baishao, 白芍) to consolidate the exterior. Deep, choppy, weak, and minute pulses without strength indicate Interior Cold, suitable for Ginseng Radix (Renshen, 人参), Atractylodis Macrocephalae Rhizoma (Baizhu, 白术), Zingiberis Rhizoma Recens (Shengjiang, 生姜), Cinnamomi Ramulus (Guizhi, 桂枝), and Aconiti Lateralis Radix Praeparata (Fuzi, 附子) to warm the interior. Surging, large, slippery, and rapid pulses with strength in Excess syndrome, presenting with macules, mania, and delirium, indicate disease in the channels, suitable for Sanhuang Shigao Tang (Three-Yellow and Gypsum Decoction) or Baihu Tang (White Tiger Decoction) for clearing and draining. Constipation with abnormal tongue coating indicates disease in the fu organs, suitable for Chaihu Daizhu Tang (Bupleurum and Rhubarb Decoction) or Chengqi Tang (Chengqi Decoction) for purging.