人身一小天地也。天有日月星辰，地有山川草木，人有五脏六腑，不外乎阴阳气化而已；
气化不能有全而无偏，有顺而无逆，故天有时而失常，地有时而荒芜，人有时而疾病。夫
病之来也，变动不一，总不越乎内证外证两端。而其致病之由，又不越乎内因外因二者
。何谓内因？喜、怒、忧、思、悲、恐、惊，七情也，阴也；何谓外因？风、寒、暑、湿、燥
、火，六气也，阳也。发于阳者，轻而易愈，发于阴者，重而难痊。内科外科，俱是一例
。今以内科论之，如疯、痨、臌、膈诸证，此发于脏者也，阴也，治之不易愈；如伤寒、疟
、痱诸证，此发于腑者也，阳也，治之易愈。伤寒之传经，在阳经者易愈，在阴经者不易愈
，夫人能知之。而外科之证，何独不然。有由脏者，有由腑者，有在皮肤肌骨者，无非血气
壅滞，营卫稽留之所致。发于脏者，其色白，其形平塌，脓水清稀，或致臭败，神色痿惫，
阴也；发于腑者，其色红而形高肿，脓水稠粘，神清气朗，阳也，此其大概也。细论之，发
于脏者为内因，不问虚实寒热，皆由气郁而成，如失营、舌疳、乳岩之类，治之得法，止可
带疾终天而已。若发于腑，即为外因，其源不一，有火热助心为疡，有寒邪伤心为疡，有燥
邪劫心为疡，有湿邪壅滞为疡，此俱系天行时气，皆当以所胜治之。又有寒邪所客，血泣不
通者，反寒热大作，烦躁酸疼而似热，热邪所胜，肉腐脓腥，甚至断筋出骨，以致声嘶色败
而似寒；又有劳汗当风，营逆肉里，而寒热难辨者。又有不内外因者，膏粱之积，狐蛊之感
，房劳之变，丹石之威，无不可作大疔，成大痈；即如误食毒物，跌压杖棒，汤火虫兽等伤
，亦皆作痈作脓，总由营气不从之所致也。然则治之奈何？亦在审其脉以辨其证而已。大约
疮疡未溃之先，脉宜有余；已溃之后，脉宜不足。有余者，毒盛也；不足者，元气虚也。倘
未溃而现不足之脉，火毒陷而元气虚也；已溃而现有余之脉，火毒盛而元气滞也。按定六部
之脉，细察虚实，其间宜寒、宜热、宜散、宜收、宜攻、宜补、宜逆、宜从，总以适事为故
，未可卤莽图治也。再疮疡之部位，其经络气血之循行，即伤寒之经络也。伤寒无定形，故
失治则变生。外证虽有一定之形，而毒瓦斯之流行亦无定位。故毒入于心则昏迷，入于肝
则痉厥，入于脾则腹疼胀，入于肺则喘嗽，入于肾，则目暗手足冷，入于六腑，亦皆各
有变象，兼证多端，七恶叠见。经曰∶治病必求其本。本者何？曰脏也，腑也，阴阳也，虚
实也，表里也，寒热也。得其本，则宜凉、宜温、宜攻、宜补，用药庶无差误；倘不得其本
，则失之毫厘，谬以千里，可不慎诸。
人体是一个小天地。天有日、月、星、辰，地有山、川、草、木，人有五脏六腑，都不外乎阴阳气化而已；
气化不可能只有全而没有偏，只有顺而没有逆，所以天有时会出现失常，地有时会出现荒芜，人有时会出现疾病。那
疾病的到来，变化不一，总不外乎内证和外证两端。而其致病的原因，也不外乎内因和外因二者
。什么是内因？喜、怒、忧、思、悲、恐、惊，这七情（七种情绪），属于阴；什么是外因？风、寒、暑、湿、燥
、火，这六气（六种气候因素），属于阳。发于阳的，病情轻浅且容易治愈，发于阴的，病情沉重且难以痊愈。内科和外科，都是一样的道理。现在以内科来论述，如疯病、痨病、臌胀、膈证等各种病证，这是发于脏的，属于阴，治疗不容易痊愈；如伤寒、疟疾、中风等病证，这是发于腑的，属于阳，治疗容易痊愈。伤寒病的传经，在阳经者容易痊愈，在阴经者不容易痊愈，这是人们所知道的。而外科的病证，为什么偏偏不是这样呢？有的由脏引起，有的由腑引起，有的在皮肤肌骨，无非是血气
壅滞，营卫稽留所致。发于脏的，其颜色白，其形态平塌，脓水清稀，或者导致臭败，神色萎靡疲惫，属于阴；发于腑的，其颜色红而形态高肿，脓水稠粘，神清气朗，属于阳，这是一般情况。详细论述的话，发
于脏的属于内因，不问虚实寒热，都是由气郁而成，如失营、舌疳、乳岩等疾病，治疗得法，只能带病终身罢了。如果发于腑，就属于外因，其源头不一，有火热助心形成疮疡，有寒邪伤心形成疮疡，有燥
邪劫心形成疮疡，有湿邪壅滞形成疮疡，这些都系天时流行之气，都应当以相克的方法治疗。又有寒邪所客，血液凝涩不
通的，反而出现寒热大作，烦躁酸疼而像热证，热邪所胜，肌肉腐烂脓液腥臭，甚至断筋露骨，以致声音嘶哑面色败坏而像寒证；又有劳作出汗当风，营气逆行入肌肉里，而寒热难以分辨的情况。又有不内外因的，膏粱厚味的积滞，狐蛊的感染
，房劳的变化，丹石药物的威力，没有不可以造成大疔，成大痈的；就像误食毒物，跌打压杖棒，汤火虫兽等伤害
，也都形成痈脓，总归是由营气不从所致。那么治疗怎么办呢？也在于审察脉象以辨别证候罢了。大约
疮疡未溃破之前，脉象宜有余；已溃破之后，脉象宜不足。有余的，是毒盛；不足的，是元气虚。如果未溃破而现出不足的脉象，是火毒内陷而元气虚；已溃破而现出有余的脉象，是火毒盛而元气滞。按定寸关尺六部
之脉，仔细察辨虚实，其间适宜用寒、适宜用热、适宜发散、适宜收敛、适宜攻下、适宜补益、适宜逆治、适宜从治，总以适合病情为准则，不可鲁莽图谋治疗。再疮疡的部位，其经络气血的循行，就是伤寒的经络。伤寒没有固定的形态，所以误治则变证丛生。外证虽然有一定的形态，而毒气的流行也没有固定位置。所以毒入于心则昏迷，入于肝
则痉厥，入于脾则腹痛腹胀，入于肺则喘咳，入于肾，则目暗手足冷，入于六腑，也都有各自的变象，兼证多端，七恶（外科危重证候）叠见。经说：治病必求其本。本是什么呢？曰脏也，腑也，阴阳也，虚
实也，表里也，寒热也。得到其根本，则适宜凉、适宜温、适宜攻、适宜补，用药才少出差错；如果得不到其根本，则失之毫厘，谬以千里，能不谨慎吗。
The human body is a microcosm. Heaven has the sun, moon, stars, and constellations; earth has mountains, rivers, grass, and trees; humans have the five zang organs (Zang organs: solid organs responsible for storing essence) and six fu organs (Fu organs: hollow organs responsible for transportation and transformation). None of these are beyond the realm of yin-yang qi transformation (Yin-Yang Qi Transformation: the dynamic process of vital energy governed by yin and yang principles).
Qi transformation cannot be entirely complete without bias, nor entirely smooth without reversal. Therefore, heaven sometimes experiences abnormalities, earth sometimes experiences barrenness, and humans sometimes experience disease. The onset of disease varies in its changes, but it never exceeds the two categories of internal manifestations (Nei Zheng: symptoms originating from internal organ dysfunction) and external manifestations (Wai Zheng: symptoms presenting on the surface or due to external pathogens). Its causes do not exceed the two categories of internal factors (Internal Factors: etiological factors originating within the body, primarily emotional) and external factors (External Factors: etiological factors originating outside the body, primarily climatic). What are internal factors? Joy, anger, worry, thought, sorrow, fear, and shock—these seven emotions (Seven Emotions: the seven types of emotional responses that can affect health), which belong to yin. What are external factors? Wind, cold, summer-heat, dampness, dryness, and fire—these six qi (Six Qi: the normal climatic conditions that become pathogenic when excessive or untimely), which belong to yang. Diseases manifesting from yang are mild and easily cured; diseases manifesting from yin are severe and difficult to cure. Internal medicine and external medicine follow the same principle. Taking internal medicine as an example, conditions such as madness (Feng: mental disorders), consumption (Lao: chronic wasting diseases), abdominal distension (Gu: ascites), and diaphragmatic obstruction (Ge: dysphagia/chest fullness) originate in the zang organs, belong to yin, and are difficult to cure. Conditions such as Shanghan (Cold Damage Disease: a category of febrile diseases caused by cold pathogens), malaria (Nue: periodic feverish illness), and stroke/paralysis (Fei: sudden loss of consciousness or motor function) originate in the fu organs, belong to yang, and are easy to cure. In the transmission of meridians in Shanghan, those in yang meridians are easy to cure, while those in yin meridians are not, which people generally know. Why should external medicine be different? Some arise from the zang organs, some from the fu organs, some in the skin, muscles, and bones; all are caused by stagnation of blood and qi (Blood and Qi Stagnation: impaired flow of blood and vital energy) and retention of Ying and Wei (Ying and Wei: Nutritive and Defensive qi, respectively). Those manifesting from the zang organs appear white, with flat lesions, clear and thin pus, possibly foul-smelling, accompanied by listless spirit and fatigue, belonging to yin. Those manifesting from the fu organs appear red with high swelling, thick and sticky pus, with clear spirit and bright eyes, belonging to yang; this is the general rule. Detailed analysis shows that those arising from the zang organs are due to internal factors; regardless of deficiency/excess or cold/heat, they result from qi depression (Qi Depression: stagnation of qi flow), such as Shiying (Shiying: malignant breast tumor), Shengan (Shengan: tongue ulcer/cancer), and Ruyan (Ruyan: breast cancer). With proper treatment, one can only live with the disease until death. If arising from the fu organs, they are due to external factors; their sources vary. Fire-heat may assist the heart to cause sores; cold evil may damage the heart to cause sores; dryness evil may rob the heart to cause sores; dampness evil may obstruct to cause sores. These are all due to epidemic seasonal qi (Epidemic Seasonal Qi: pathogenic climate factors prevalent during specific seasons) and should be treated according to the principle of mutual overcoming (Mutual Overcoming: the controlling relationship among the Five Elements). Additionally, when cold evil lodges, causing blood stasis and blockage, it may paradoxically present with severe alternating chills and fever, irritability, soreness, and pain resembling heat syndrome. When heat evil prevails, flesh rots with foul pus, even severing tendons and exposing bone, leading to hoarseness and sallow complexion resembling cold syndrome. There are also cases where sweat from labor meets wind, causing Ying qi to reverse into the muscle layer, making cold and heat difficult to distinguish. Furthermore, there are neither-internal-nor-external factors: accumulation from rich and sweet foods, infection from parasites/toxins, changes from sexual exhaustion, and toxicity from cinnabar/mineral drugs—all can lead to large Ding (Ding: deep-seated, hard boil) or Da Yong (Da Yong: large abscess). Even if poisoned by ingesting toxic substances, injured by falls/beating, or burned/bitten by hot water/fire/insects/animals, all result in sores and pus, ultimately caused by the non-compliance of Ying qi (Ying Qi Non-compliance: failure of nutritive qi to circulate harmoniously). So how should they be treated? It lies in examining the pulse to differentiate the syndrome. Generally, before the sore ulcerates, the pulse should be surplus (Excess Pulse: indicating excess pathogen); after ulceration, the pulse should be deficient (Deficient Pulse: indicating deficiency of healthy qi). Surplus indicates abundant toxin; deficient indicates deficient yuan qi (Yuan Qi: Original/Primordial Qi). If a deficient pulse appears before ulceration, it means fire-toxin has collapsed inward and yuan qi is deficient; if a surplus pulse appears after ulceration, it means fire-toxin is abundant and yuan qi is stagnant. By fixing the six positions (Six Positions: Cun, Guan, Chi on both wrists) of the pulse and carefully observing deficiency and excess, one must determine whether to use cold, heat, dispersion, consolidation, purgation, tonification, counter-treatment, or following-treatment. The ultimate goal is appropriateness to the condition; one must not treat rashly. Regarding the location of sores, the circulation of meridians and blood/qi is the same as in Shanghan. Shanghan has no fixed form, so mismanagement leads to complications. Although external signs have a certain form, the spread of toxic vapors (Toxic Vapors: pathogenic heat/toxins) has no fixed position. Thus, if toxin enters the heart, there is coma; if it enters the liver, there is spasm and syncope; if it enters the spleen, there is abdominal pain and distension; if it enters the lungs, there is wheezing and cough; if it enters the kidneys, there is dim vision and cold hands/feet; if it enters the six fu organs, each has its own variations, with many concurrent syndromes and repeated occurrences of the Seven Evils (Seven Evils: seven critical prognostic signs in surgery). The Classic says: "In treating disease, one must seek the root." What is the root? It is the zang organs, fu organs, yin and yang, deficiency and excess, interior and exterior, cold and heat. Grasping the root allows for appropriate use of cooling, warming, purging, and tonifying methods, minimizing medication errors. Failing to grasp the root results in a slight deviation leading to a thousand-mile error; can one not be cautious?