望者看形色也。闻者听声音也。问者访病情也。切者诊六脉也。四事本不可缺一。而唯望与
问为最要。何也。盖闻声一道。不过审其音之低高。以定虚实。嗽之闷爽。以定升降。其他则无
可闻者。切脉一道。不过辨其浮沉以定表里。迟数以定寒热。强弱以定虚实。其他则胸中了
了。指下难明。且时大时小。忽浮忽沉。六脉亦难定准。故医家谓据脉定症。是欺人之论也。惟
细问情由。则先知病之来历。细问近状。则又知病之深浅。而望其部位之色。望其唇舌之色。
望其大小便之色。病情已得八九矣。而再切其脉。合诸所问所望。果相符否。稍有疑义。则默
思其故。两两相形。虚与实相形。寒与热相形。表与里相形。其中自有把握之处。即可定断。慎
斯术也以往。其无所失矣。
凡人之病。不外乎阴阳。而阴阳之分。总不离乎表里虚实寒热六字尽之。夫里为阴。表为阳。
虚为阴。实为阳。寒为阴。热为阳。良医之救人。不过能辨此阴阳而已。庸医之杀人。不过错认
此阴阳而已。假如发热恶寒。鼻塞咳嗽。头痛。脉浮。舌无苔。口不渴。此病之在表者也。如或潮
热恶热。口燥。舌黄。腹痛便涩。脉沉。此病之在里者也。假如气短体弱。多汗惊悸。手接心腹。四
肢畏冷。脉来无力。此病之本虚者也。若病中无汗。或狂躁不卧。腹胀拒按。脉实有力。此病之
又实者也。假如唇舌俱白。口不渴。喜饮热汤。鼻流清涕。小便清。大便溏。手足冷。脉迟。此病之
犯寒者也。若舌赤目红。口渴喜冷。烦躁。溺短便秘。或唇燥舌干。此病之患热者也。凡此皆阴
阳之分也。至于邪盛正衰。阴虚火亢等。则又阴中之阳。阳中之阴。其间毫厘千里。命在反掌。
辨之者安得而不慎。
表治宜发散也。如初感风寒。发热头痛。但用苏梗一钱五分。荆芥一钱五分。防风一钱。川芎一钱。甘草
五分。生姜二片以散之。头痛甚。加羌活六分。如鼻塞或流清涕。加半夏一钱五分。茯苓、陈皮各一钱。如
咳嗽。则加桔梗七分。杏仁三钱。前胡一钱之类。一剂得汗而热即退。不必再服。但避风寒。忌油腻。未得
汗则再剂而止。若寒热往来。欲作疟状。宜用柴胡八分。酒芩八分。赤芍一钱。制半夏一钱五分。甘草五
分。大枣三枚。生姜三片以和之。虚者加防党二钱。此其症在表。切勿妄用枳壳、神曲、麦芽消导之药。引
邪入内。
里治宜归经也。有虚实。有寒热。宜辨其病在何脏腑而治之。法详脏腑门。惟喜怒忧思悲恐惊谓之七
情。此里症之最难治者。但宽其心而药始效。否则无益也。然症在于里。大忌发散。散之则虚者汗脱。热
者煽炽。医家动辄用表。可惧哉。
虚治宜补也。然有阴虚。有阳虚。血虚者为阴虚。宜补其血。轻者用生地四钱。首乌二钱。归身一钱五分。
酒芍一钱五分。炙鳖甲二钱。 豆皮三钱。海参三钱。北沙参三钱之类。重者用熟地五钱。枸杞三钱。五
味七分。萸肉一钱。菟丝一钱以填之。气虚者为阳虚。宜补其气。轻者用党参三钱。白术二钱。山药二钱。
茯苓一钱五分。炙草六分。红枣六枚。生姜一片之类。重者用人参一钱。黄 一钱五分以振之。气欲脱
则并加附子二钱。干姜二钱以回阳。若气血兼虚。则阴阳并补。八珍汤、十全大补汤。皆圣药也。
实治宜泻也。心有火邪。肺有风寒。脾有食积、虫痞、湿热。肝有郁怒之气。胆胃包络膀胱大小肠各能受
邪。皆为实症。治法详各脏腑门。然治实以速为功。苟迁延日久。病未去而元气虚。则难以消导矣。
寒治宜温也。寒在表则恶风寒。宜苏叶一钱。藿梗二钱。荆芥、防风各一钱。前胡一钱五分。杏仁三钱。生
姜三片之属。以散其邪。甚则桂枝五分。麻黄五分。细辛六分。寒在里则喜热汤。宜制夏二钱。藿香一钱
五分。焦术一钱五分。制朴一钱。吴茱萸八分。焦谷芽三钱。煨姜二片。砂仁二粒之属。以暖其中。甚则附
子六分。肉桂六分。干姜六分。凡寒症唇舌必白。脉迟便利。腹或冷痛。一投寒凉。入口立脱。慎之。
热治宜凉也。然热症有实火。有虚火。实火之症。或因外感。或因内郁所致。宜分脏腑治之。火之微者。黑
山栀一钱五分。石斛三钱。地骨皮二钱。青蒿一钱五分。丹皮一钱。连翘一钱五分。麦冬二钱。花粉一钱
五分。银花三钱。竹叶五分。灯心一握之属。甚者加黄连七分。黄芩一钱五分。或石膏四钱。知母一钱五
分。极甚则用大黄一钱五分。龙胆草七分等。虚火之症。或阳虚外热。口不渴。唇不红。脉不数。宜四君子
汤。以补其阳。若阴虚内热。舌或绛。头或痛。目或干。过午便热。宜四物汤、六味地黄汤。以补其阴。
望诊是观察患者的神色和形态。闻诊是听取患者的声音。问诊是询问病情。切诊是诊察六脉。这四项诊疗方法本来缺一不可，但唯独望诊和问诊最为重要。为什么呢？因为闻声这一项，不过是审察声音的高低，以此判断虚实；咳嗽的闷塞或清爽，以此判断气机的升降。其他方面就没有什么可听的了。切脉这一项，不过是辨别脉象的浮沉以判断表里，迟数以判断寒热，强弱以判断虚实。其他方面则心中虽然明白，但手指下却难以明确分辨。而且脉象有时大有时小，忽浮忽沉，六脉也难以准确判定。所以医家说“仅凭脉象就能确定病症”，这是欺骗人的言论。只有详细询问病因，才能预先知道疾病的来龙去脉；详细询问近期状况，又能知道疾病的深浅程度。再观察患病部位的颜色、嘴唇和舌头的颜色、大小便的颜色，病情就已经掌握了八九成。然后再切脉，结合所问和所望的情况，看是否相符。如果有丝毫疑问，就默默思考其中的原因，将虚与实、寒与热、表与里两两对比参照，其中自然有把握之处，就可以做出诊断。谨慎地运用这种医术前行，就不会有什么过失了。
大凡人的疾病，不外乎阴阳。而阴阳的区分，总离不开表、里、虚、实、寒、热这六个字来概括。里属于阴，表属于阳；虚属于阴，实属于阳；寒属于阴，热属于阳。高明的医生救人，不过能辨别这些阴阳罢了；庸俗的医生杀人，不过是错认了这些阴阳罢了。假如出现发热恶寒、鼻塞咳嗽、头痛、脉浮、舌无苔、口不渴等症状，这是病在表证。如果出现潮热恶热、口燥、舌黄、腹痛大便涩滞、脉沉等症状，这是病在里证。假如出现气短体弱、多汗惊悸、手护心腹部、四肢畏冷、脉来无力等症状，这是本虚证。如果在病中无汗，或者狂躁不能卧、腹胀拒按、脉实有力，这是又一种实证。假如唇舌都发白、口不渴、喜欢喝热汤、鼻流清涕、小便清长、大便溏薄、手足冷、脉迟，这是受寒证。如果舌头红赤、眼睛发红、口渴喜冷饮、烦躁、尿短便秘、或者嘴唇干燥舌头干裂，这是患热证。以上这些都是阴阳的区分。至于邪气盛正气衰、阴虚火亢等情况，则是阴中之阳、阳中之阴，其间相差毫厘千里，性命只在反掌之间。辨别的人怎么能不谨慎呢？
表证的治疗适宜用发散法。如初次感受风寒，出现发热头痛，只用苏梗一钱五分、荆芥一钱五分、防风一钱、川芎一钱、甘草五分、生姜两片来发散。如果头痛严重，加羌活六分。如果鼻塞或流清涕，加半夏一钱五分、茯苓和陈皮各一钱。如果咳嗽，则加桔梗七分、杏仁三钱、前胡一钱等。服一剂后出汗且热退，不必再服，只要避开风寒，忌食油腻。如果没有出汗，则再服一剂即止。如果是寒热往来，想要发作疟疾的样子，宜用柴胡八分、酒炒黄芩八分、赤芍一钱、制半夏一钱五分、甘草五分、大枣三枚、生姜三片来和解。体虚者加党参二钱。此症在表，千万不要妄用枳壳、神曲、麦芽等消导药物，以免引邪入内。
里证的治疗适宜归经治疗。有虚有实，有寒有热，应当辨别病在哪个脏腑而进行治疗，方法详见脏腑门。只是喜怒忧思悲恐惊称为七情，这是里证中最难治疗的。只有宽慰其心情，药物才能见效，否则没有益处。然而症状在里，最忌讳发散。发散则虚者会导致汗脱，热者会使火势炽盛。医家动不动就用解表药，真是可怕啊。
虚证的治疗适宜用补益法。但有阴虚和阳虚之分。血虚属于阴虚，适宜补血。轻者用地黄四钱、首乌二钱、当归身一钱五分、酒白芍一钱五分、炙鳖甲二钱、豆皮三钱、海参三钱、北沙参三钱等。重者用熟地黄五钱、枸杞子三钱、五味子七分、山茱萸一钱、菟丝子一钱来填补。气虚属于阳虚，适宜补气。轻者用党参三钱、白术二钱、山药二钱、茯苓一钱五分、炙甘草六分、红枣六枚、生姜一片等。重者用人参一钱、黄芪一钱五分来振奋。如果气欲脱，则并加附子二钱、干姜二钱来回阳救逆。如果气血兼虚，则阴阳并补，八珍汤、十全大补汤都是极好的药方。
实证的治疗适宜用泻下法。心有火邪，肺有风寒，脾有食积、虫积痞块、湿热，肝有郁怒之气，胆、胃、心包络、膀胱、大肠、小肠都能受邪，都属于实证。治法详见各脏腑门。然而治疗实证以迅速为功效，如果拖延日久，病未去除而元气已虚，那就难以消导了。
寒证的治疗适宜用温法。寒在表则恶风寒，宜用苏叶一钱、藿梗二钱、荆芥和防风各一钱、前胡一钱五分、杏仁三钱、生姜三片等来发散邪气。严重时加桂枝五分、麻黄五分、细辛六分。寒在里则喜欢热汤，宜用制半夏二钱、藿香一钱五分、焦白术一钱五分、制厚朴一钱、吴茱萸八分、焦谷芽三钱、煨姜二片、砂仁二粒等来温暖中焦。严重时加附子六分、肉桂六分、干姜六分。凡是寒证，唇舌必然发白，脉迟且便利，腹部或冷痛。一旦投用寒凉药，入口立即导致阳气脱失。务必谨慎。
热证的治疗适宜用凉法。然而热证有实火和虚火之分。实火的病症，或因外感，或因内郁所致，应当分脏腑治疗。火轻微的，用黑山栀一钱五分、石斛三钱、地骨皮二钱、青蒿一钱五分、丹皮一钱、连翘一钱五分、麦冬二钱、花粉一钱五分、银花三钱、竹叶五分、灯心一握等。严重的加黄连七分、黄芩一钱五分，或者石膏四钱、知母一钱五分。极严重的用大黄一钱五分、龙胆草七分等。虚火的病症，或者是阳虚外热，口不渴，唇不红，脉不数，宜用四君子汤来补其阳。如果是阴虚内热，舌可能绛红，头可能痛，目可能干，午后发热，宜用四物汤、六味地黄汤来补其阴。
Inspection involves observing the patient's complexion and physical form. Auscultation and olfaction involve listening to the patient's voice. Inquiry involves asking about the condition of the illness. Palpation involves examining the six pulses. These four methods are originally indispensable, yet inspection and inquiry are the most crucial. Why? Because auscultation merely assesses the pitch of the voice to determine Deficiency (Xu) or Excess (Shi), and the quality of coughing—whether stifled or clear—to determine the movement of Qi (ascending or descending). There is little else to hear. Regarding pulse diagnosis, it merely distinguishes floating and sinking pulses to determine Exterior (Biao) or Interior (Li), slow and rapid rates to determine Cold (Han) or Heat (Re), and strong and weak forces to determine Deficiency or Excess. Other aspects may be clear in mind but difficult to discern under the fingers. Moreover, pulses can vary in size from large to small, appearing suddenly floating or suddenly sinking, making the six pulses hard to standardize. Therefore, the claim by some physicians that "symptoms can be determined solely by the pulse" is a deceptive argument. Only by carefully inquiring into the cause can one know the origin of the disease; by carefully inquiring into recent conditions, one can know the depth of the disease. By inspecting the color of the affected area, the lips, the tongue, and the urine and stool, one has grasped eight or nine-tenths of the clinical picture. Then, palpating the pulse and combining it with the information from inquiry and inspection, one checks for consistency. If any doubt remains, one silently reflects on the reasons, comparing Deficiency with Excess, Cold with Heat, and Exterior with Interior. There will naturally be a point of certainty, allowing for a diagnosis. Practicing this art with caution ensures no errors.
Generally, human diseases do not go beyond Yin and Yang. The differentiation of Yin and Yang is summarized entirely by the six characters: Exterior, Interior, Deficiency, Excess, Cold, and Heat. Interior belongs to Yin, Exterior belongs to Yang; Deficiency belongs to Yin, Excess belongs to Yang; Cold belongs to Yin, Heat belongs to Yang. A skilled physician saves lives merely by distinguishing these Yin and Yang aspects. An incompetent physician causes death merely by misidentifying these Yin and Yang aspects. For instance, if there are symptoms of fever with aversion to cold, nasal congestion, coughing, headache, floating pulse, tongue without coating, and no thirst, this is an Exterior syndrome. If there are tidal fever with aversion to heat, dry mouth, yellow tongue coating, abdominal pain with difficult bowel movements, and a sinking pulse, this is an Interior syndrome. If there is shortness of breath, physical weakness, excessive sweating, palpitations, guarding the heart and abdomen, cold limbs, and a powerless pulse, this is a Root Deficiency syndrome. If during the illness there is no sweat, or mania/restlessness preventing sleep, abdominal distension with refusal to press, and a solid and forceful pulse, this is another type of Excess syndrome. If the lips and tongue are white, there is no thirst, a preference for hot drinks, clear runny nose, clear urine, loose stools, cold hands and feet, and a slow pulse, this is a Cold invasion syndrome. If the tongue is red, eyes are red, there is thirst with a preference for cold drinks, irritability, scanty dark urine, constipation, or dry lips and cracked tongue, this is a Heat syndrome. All these are differentiations of Yin and Yang. As for conditions such as excess pathogen with deficient healthy Qi, or Yin deficiency with hyperactive Fire, these represent Yin within Yang and Yang within Yin. The difference between them is like a hair's breadth versus a thousand miles, and life hangs in the balance. How can those who differentiate them not be cautious?
The treatment for Exterior syndromes should favor dispersing methods. For example, upon initial contraction of Wind-Cold, presenting with fever and headache, use only Perillae Caulis (Sugeng) 1.5 qian, Schizonepetae Herba (Jingjie) 1.5 qian, Saposhnikoviae Radix (Fangfeng) 1 qian, Ligusticum Chuanxiong Rhizoma (Chuanxiong) 1 qian, Glycyrrhizae Radix et Rhizoma (Gancao) 0.5 qian, and two slices of Zingiberis Rhizoma Recens (Shengjiang) to disperse. If the headache is severe, add Notopterygii Rhizoma et Radix (Qianghuo) 0.6 qian. If there is nasal congestion or clear rhinorrhea, add Pinelliae Rhizoma Preparatum (Banxia) 1.5 qian, Poria (Fuling) and Citri Reticulatae Pericarpium (Chenpi) each 1 qian. If there is coughing, add Platycodonis Radix (Jiegeng) 0.7 qian, Armeniacae Semen Amarum (Xingren) 3 qian, and Peucedani Radix (Qianhu) 1 qian, etc. After one dose, if sweating occurs and fever subsides, no further administration is needed; simply avoid wind and cold, and avoid greasy food. If sweating does not occur, administer a second dose and then stop. If there are alternating chills and fever, resembling malaria, use Bupleuri Radix (Chaihu) 0.8 qian, Scutellariae Radix prepared with wine (Huangqin) 0.8 qian, Paeoniae Radix Rubra (Chishao) 1 qian, Pinelliae Rhizoma Preparatum (Banxia) 1.5 qian, Glycyrrhizae Radix et Rhizoma (Gancao) 0.5 qian, three Jujubae Fructus (Dazao), and three slices of Zingiberis Rhizoma Recens (Shengjiang) to harmonize. For deficient patients, add Codonopsis Radix (Dangshen) 2 qian. Since the syndrome is at the Exterior, do not recklessly use digestive agents such as Aurantii Fructus (Zhike), Massae Fermentatae Medicinalis (Shenqu), or Hordeum Germinatum (Maiya) to avoid drawing the pathogen inward.
The treatment for Interior syndromes should focus on directing herbs to the meridians/organs. There are Deficiency and Excess, Cold and Heat; one must distinguish which Zang-Fu organ is affected and treat accordingly (see the Zang-Fu section for details). However, Joy, Anger, Worry, Overthinking, Sorrow, Fear, and Fright are called the Seven Emotions, which constitute the most difficult-to-treat Interior syndromes. One must soothe the mind for the medication to take effect; otherwise, it is useless. Furthermore, when symptoms are Interior, dispersing methods are strictly contraindicated. Dispersing will cause sweat collapse in Deficient cases and exacerbate Fire in Heat cases. It is terrifying that physicians often resort to Exterior-dispersing methods indiscriminately.
The treatment for Deficiency syndromes should favor tonification. There are Yin Deficiency and Yang Deficiency. Blood Deficiency is considered Yin Deficiency and requires blood tonification. For mild cases, use Rehmanniae Radix Preparata (Shengdi) 4 qian, Polygoni Multiflori Caulis (Shouwu) 2 qian, Angelicae Sinensis Radix (Guishen) 1.5 qian, Paeoniae Radix Alba prepared with wine (Jiushao) 1.5 qian, Testudinis Carapax et Plastrum calcined (Zhibiejia) 2 qian, Doupi 3 qian, Sea Cucumber (Haishen) 3 qian, and Glehniae Radix (Beishashen) 3 qian, etc. For severe cases, use Rehmanniae Radix Preparata (Shudi) 5 qian, Lycii Fructus (Gouqi) 3 qian, Schisandrae Fructus (Wuweizi) 0.7 qian, Corni Fructus (Yurou) 1 qian, and Cuscutae Semen (Tusizi) 1 qian to fill and nourish. Qi Deficiency is considered Yang Deficiency and requires Qi tonification. For mild cases, use Codonopsis Radix (Dangshen) 3 qian, Atractylodis Macrocephalae Rhizoma (Baizhu) 2 qian, Dioscoreae Rhizoma (Shanyao) 2 qian, Poria (Fuling) 1.5 qian, Glycyrrhizae Radix et Rhizoma calcined (Zhigancao) 0.6 qian, six Jujubae Fructus (Hongzao), and one slice of Zingiberis Rhizoma Recens (Shengjiang), etc. For severe cases, use Ginseng Radix et Rhizoma (Renshen) 1 qian and Astragali Radix (Huangqi) 1.5 qian to uplift. If Qi is about to collapse, add Aconiti Lateralis Radix Preparata (Fuzi) 2 qian and Zingiberis Rhizoma (Ganjiang) 2 qian to restore Yang. If both Qi and Blood are deficient, tonify both Yin and Yang simultaneously; Ba Zhen Tang (Eight Treasures Decoction) and Shi Quan Da Bu Tang (Ten Significant Tonifying Decoction) are excellent formulas.
The treatment for Excess syndromes should favor purging/draining. Heart Fire Evil, Lung Wind-Cold, Spleen Food Stagnation/Parasitic Obstruction/Damp-Heat, Liver Qi Stagnation due to Anger, and pathogens affecting the Gallbladder, Stomach, Pericardium, Bladder, Large Intestine, and Small Intestine all constitute Excess syndromes. Treatment methods are detailed in the respective Zang-Fu sections. However, treating Excess requires speed; if delayed, the pathogen remains while Healthy Qi becomes deficient, making digestion/purging difficult.
The treatment for Cold syndromes should favor warming. Cold at the Exterior presents with aversion to wind and cold; use Perillae Folium (Suye) 1 qian, Agastaches Herba (Huogeng) 2 qian, Schizonepetae Herba (Jingjie) and Saposhnikoviae Radix (Fangfeng) each 1 qian, Peucedani Radix (Qianhu) 1.5 qian, Armeniacae Semen Amarum (Xingren) 3 qian, and three slices of Zingiberis Rhizoma Recens (Shengjiang) to disperse the pathogen. In severe cases, add Cinnamomi Ramulus (Guizhi) 0.5 qian, Ephedrae Herba (Mahuang) 0.5 qian, and Asari Radix et Rhizoma (Xixin) 0.6 qian. Cold at the Interior presents with a preference for hot drinks; use Pinelliae Rhizoma Preparatum (Banxia) 2 qian, Agastache Herba (Huoxiang) 1.5 qian, Atractylodis Macrocephalae Rhizoma fried (Jiaozhu) 1.5 qian, Magnoliae Officinalis Cortex preparated (Zhipu) 1 qian, Evodiae Fructus (Wuzhuyu) 0.8 qian, Hordeum Germinatum fried (Jiaoguya) 3 qian, Zingiberis Rhizoma baked (Weijiang) 2 slices, and Amomi Fructus (Sharen) 2 grains to warm the Middle. In severe cases, add Aconiti Lateralis Radix Preparata (Fuzi) 0.6 qian, Cinnamomi Cortex (Rougui) 0.6 qian, and Zingiberis Rhizoma (Ganjiang) 0.6 qian. In all Cold syndromes, the lips and tongue are white, the pulse is slow, bowels are loose, and the abdomen may be cold and painful. Administering Cold/Cooling herbs immediately leads to collapse. Be extremely cautious.
The treatment for Heat syndromes should favor cooling. However, Heat syndromes include Excess Fire and Deficient Fire. Excess Fire may result from external contraction or internal stagnation; treat according to the affected Zang-Fu organs. For mild Fire, use Gardeniae Fructus nigricans (Heishanzhi) 1.5 qian, Dendrobii Caulis (Shihu) 3 qian, Lycii Cortex (Digupi) 2 qian, Artemisiae Annuae Herba (Qinghao) 1.5 qian, Moutan Cortex (Danpi) 1 qian, Forsythiae Fructus (Lianqiao) 1.5 qian, Ophiopogonis Radix (Maidong) 2 qian, Trichosanthis Radix (Huafen) 1.5 qian, Lonicerae Japonicae Flos (Yinhua) 3 qian, Menthae Haplocalycis Herba (Zhuye) 0.5 qian, and Junci Medulla (Dengxin) a handful. For severe cases, add Coptidis Rhizoma (Huanglian) 0.7 qian, Scutellariae Radix (Huangqin) 1.5 qian, or Gypsum Fibrosum (Shigao) 4 qian and Anemarrhenae Rhizoma (Zhimu) 1.5 qian. For extreme cases, use Rhei Radix et Rhizoma (Dahuang) 1.5 qian and Gentianae Radix (Longdancao) 0.7 qian, etc. For Deficient Fire, if it is Yang Deficiency with exterior Heat (no thirst, non-red lips, non-rapid pulse), use Si Jun Zi Tang (Four Gentlemen Decoction) to tonify Yang. If it is Yin Deficiency with interior Heat (crimson tongue, possible headache, dry eyes, afternoon fever), use Si Wu Tang (Four Substances Decoction) or Liu Wei Di Huang Tang (Six Ingredient Pill with Rehmannia) to tonify Yin.