病有总要，寒、热、虚、实、表、里、阴、阳，八字而已。病情既不外此，则辨证之法
亦不出此。一病之寒热，全在口渴与不渴，渴而消水与不消水，饮食喜热与喜冷，烦躁与
厥逆，溺之长短、赤白，便之溏结，脉之迟数以分之。假如口渴而能消水，喜冷冻饮料食，烦躁
溺短赤，便结，脉数，此热也。假如口不渴，或假渴而不能消水，喜饮热汤，手足厥冷，
溺清长，便溏，脉迟，此寒也。
一病之虚实，全在有汗与无汗，胸腹胀痛与否，胀之减与不减，痛之拒按与喜按，病之
新久，禀之浓薄，脉之虚实以分之。假如病中无汗，腹胀不减，痛而拒按，病新得，人禀浓
脉实有力，此实也。假如病中多汗，腹胀时减，复如故，痛而喜按，按之则痛止，病久，
禀弱，脉虚无力，此虚也。
一病之表里，全在发热与潮热，恶寒与恶热，头痛与腹痛，鼻塞与口燥，舌苔之有无，
脉之浮沉以分之。假如发热恶寒，头痛鼻塞，舌上无胎，脉息浮，此表也。假如潮热恶热，
腹痛口燥，舌苔黄黑，脉息沉，此里也。
至于病之阴阳，统上六字而言，所包者广。热者为阳，实者为阳，在表者为阳；寒者为
阴，虚者为阴，在里者为阴。寒邪客表，阳中之阴；热邪入里，阴中之阳。寒邪入里，阴中
之阴；热邪达表，阳中之阳。而真阴、真阳之别，则又不同。假如脉数无力，虚火时炎，口
燥唇焦，内热便结，气逆上冲，此真阴不足也；假如脉大无力，四肢倦怠，唇淡口和，肌冷
便溏，饮食不化，此真阳不足也。
寒、热、虚、实、表、里、阴、阳之别，总不外此。然病中有热证而喜热饮者，同气相
求也。有寒证而喜冷冻饮料，却不能饮者，假渴之象也。有热证而大便溏泻者，挟热下利也。有
寒证而大便反硬者，名曰阴结也。有热证而手足厥冷者，所谓热深厥亦深、热微厥亦微是也
有寒证而反烦躁，欲坐卧泥水之中者，名曰阴躁也。有有汗而为实证者，热邪传里也。有
无汗而为虚证者，津液不足也。有恶寒而为里证者，直中于寒也。有恶热、口渴而为表证者
温热之病自里达表也。此乃阴阳变化之理，为治病之权衡，尤辨之不可不早也。
疾病的要领，归结为寒、热、虚、实、表、里、阴、阳这八个字而已。病情既然不出这个范围，那么辨证的方法也不出这个范围。判断一个病症的寒热，完全依据口渴与否、喝水后能否消化、饮食喜欢热的还是冷的、是否烦躁或四肢厥冷、小便长短及颜色赤白、大便溏泄或干结、脉搏迟数来区分。假如口渴且能饮水消化，喜欢冷冻饮料食物，烦躁，小便短赤，大便干结，脉搏快，这是热证。假如口不渴，或者假性口渴但不能饮水，喜欢喝热汤，手足冰冷，小便清长，大便溏泄，脉搏慢，这是寒证。
判断一个病症的虚实，完全依据有汗与无汗、胸腹胀痛与否、胀感是否减轻、疼痛是拒按还是喜按、病程新久、体质强弱、脉搏虚实来区分。假如病中无汗，腹胀不减轻，疼痛拒按，病是新得的，人体质强壮，脉搏实而有力，这是实证。假如病中多汗，腹胀有时减轻但随后又恢复原状，疼痛喜按，按压则疼痛停止，病程久，体质弱，脉搏虚而无力，这是虚证。
判断一个病症的表里，完全依据发热与潮热（定时发热）、恶寒与恶热、头痛与腹痛、鼻塞与口燥、舌苔有无、脉搏浮沉来区分。假如发热恶寒，头痛鼻塞，舌上无苔，脉搏浮，这是表证。假如潮热恶热，腹痛口燥，舌苔黄黑，脉搏沉，这是里证。
至于病症的阴阳，总括上述六字而言，所涵盖的内容很广。热证属于阳，实证属于阳，在表属于阳；寒证属于阴，虚证属于阴，在里属于阴。寒邪客居体表，是阳中之阴；热邪深入体内，是阴中之阳。寒邪深入体内，是阴中之阴；热邪达于体表，是阳中之阳。而真阴、真阳的区别，则又不相同。假如脉搏快但无力，虚火时常上炎，口燥唇焦，内热大便干结，气逆上冲，这是真阴不足；假如脉搏大但无力，四肢倦怠，嘴唇淡色口中调和，肌肤寒冷大便溏泄，饮食不化，这是真阳不足。
寒、热、虚、实、表、里、阴、阳的区别，总不外乎这些。然而病中有热证却喜欢热饮的，是同气相求。有寒证却喜欢冷冻饮料食物，却不能饮用的，是假渴的现象。有热证却大便溏泻的，是挟热下利。有寒证却大便反硬的，名叫阴结。有热证却手足冰冷的，就是所谓“热深厥亦深、热微厥亦微”。有寒证却反而烦躁，想要坐卧在泥水中的，名叫阴躁。有有汗却表现为实证的，是热邪传入体内。有无汗却表现为虚证的，是津液不足。有恶寒却表现为里证的，是直中于寒。有恶热、口渴却表现为表证的，是温热病从体内达于体表。这是阴阳变化的道理，是治病的权衡标准，尤其不可不早辨明。
The essentials of disease can be summarized in eight characters: Cold, Heat, Deficiency, Excess, Exterior, Interior, Yin, and Yang. Since pathological conditions do not fall outside this scope, the methods for syndrome differentiation also do not exceed it. To distinguish the Cold or Heat of a specific disease, one relies entirely on thirst or lack thereof, whether ingested water is consumed/digested, preference for hot or cold food and drink, presence of irritability or cold extremities (Jue Ni), length and color (red or pale) of urine, consistency of stool (loose or hard), and pulse rate (slow or rapid). For instance, if there is thirst with ability to consume fluids, preference for cold drinks/food, irritability, short red urine, hard stool, and a rapid pulse, this indicates Heat. Conversely, if there is no thirst, or false thirst without ability to consume fluids, preference for hot soups/drinks, cold hands and feet, clear and long urine, loose stool, and a slow pulse, this indicates Cold.
To distinguish the Deficiency or Excess of a specific disease, one relies entirely on presence or absence of sweating, presence or absence of chest/abdominal distension and pain, whether distension subsides or persists, whether pain rejects pressure or welcomes pressure, duration of the illness (new vs. old), constitution (robust vs. weak), and pulse quality (excess or deficient). For example, if there is no sweating during the illness, abdominal distension does not subside, pain rejects pressure, the illness is recent, the constitution is robust, and the pulse is excess and forceful, this indicates Excess. Conversely, if there is profuse sweating, abdominal distension temporarily subsides but returns, pain welcomes pressure and ceases upon pressing, the illness is chronic, the constitution is weak, and the pulse is deficient and weak, this indicates Deficiency.
To distinguish the Exterior or Interior location of a specific disease, one relies entirely on fever versus tidal fever (fever at fixed times), aversion to cold versus aversion to heat, headache versus abdominal pain, nasal congestion versus dry mouth, presence or absence of tongue coating, and pulse depth (floating or sunken). For instance, if there is fever with aversion to cold, headache, nasal congestion, no tongue coating, and a floating pulse, this indicates an Exterior syndrome. Conversely, if there is tidal fever with aversion to heat, abdominal pain, dry mouth, yellow or black tongue coating, and a sunken pulse, this indicates an Interior syndrome.
Regarding Yin and Yang in disease, they encompass the aforementioned six categories broadly. Heat belongs to Yang, Excess belongs to Yang, and Exterior location belongs to Yang; Cold belongs to Yin, Deficiency belongs to Yin, and Interior location belongs to Yin. When Cold pathogen lodges in the Exterior, it is Yin within Yang; when Heat pathogen enters the Interior, it is Yang within Yin. When Cold pathogen enters the Interior, it is Yin within Yin; when Heat pathogen reaches the Exterior, it is Yang within Yang. However, the distinction between True Yin and True Yang differs. For instance, if the pulse is rapid but forceless, deficiency fire flares intermittently, mouth and lips are dry, internal heat causes hard stool, and Qi rebels upward, this indicates insufficiency of True Yin. Conversely, if the pulse is large but forceless, limbs are fatigued, lips are pale and mouth feels harmonious, skin is cold, stool is loose, and food is not digested, this indicates insufficiency of True Yang.
The distinctions among Cold, Heat, Deficiency, Excess, Exterior, Interior, Yin, and Yang generally follow these principles. However, some cases present Heat syndromes yet prefer hot drinks due to "like attracting like." Some cases present Cold syndromes yet crave cold drinks but cannot swallow them, which is a sign of false thirst. Some cases present Heat syndromes yet have loose stools, known as diarrhea with accompanying Heat. Some cases present Cold syndromes yet have hard stools, named Yin Constipation (Yin Jie). Some cases present Heat syndromes yet have cold extremities, illustrating the principle that "the deeper the heat, the deeper the cold extremities; the milder the heat, the milder the cold extremities." Some cases present Cold syndromes yet exhibit irritability, desiring to sit or lie in mud or water, named Yin Restlessness (Yin Zao). Some cases with sweating manifest as Excess syndromes due to Heat pathogen transmitting to the Interior. Some cases without sweating manifest as Deficiency syndromes due to insufficiency of Body Fluids (Jin Ye). Some cases with aversion to cold manifest as Interior syndromes due to direct invasion by Cold. Some cases with aversion to heat and thirst manifest as Exterior syndromes because Warm-Heat diseases emerge from the Interior to the Exterior. These are the principles of Yin-Yang transformation and serve as the standard for treatment; therefore, early differentiation is particularly crucial.