上古之人，其知道者，法于阴阳，合于术数，〔养生之法。〕食饮有节，起居有常，不妄作劳
，故能形与神俱，〔神去，其形则死。〕而尽终其天年，度百岁乃去。今时之人，以酒为浆，以妄
为常，醉以入房，以欲竭其精，以耗散其真，不知持满，〔满心倾覆。〕不时御神，〔神必外
驰。〕务快其心，逆于生乐，起居无节，故半百而衰也。
夫上古圣人之教下也，皆谓之虚邪贼风，避之有时，〔此治外之道也。〕恬 虚无，〔恬 者，
泊然不愿乎其外，虚无者，漠然无所动于中也。〕真气从之，精神内守，病安从来。〔此治内之道
也。〕圣人不治已病，治未病；不治已乱，治未乱。〔即上工救其萌芽也。〕夫病已成而后药
之，乱已成而后治之，譬犹渴而穿井，斗而铸兵，不亦晚乎。
阴阳者，天地之道，万物之纲，变化之父母，〔变化虽
多，皆阴阳之所主。〕生杀之本始，〔生杀之道，阴阳而已。〕治病必求其本。〔病变无穷，皆不外
阴阳，知病所由生，而直取之乃为其治。〕阴静阳躁，阴生阳长，〔阳不独立，得阴而后成，如发生赖
于阳和，而长养由乎雨露。〕阳杀阴藏。〔阴不自专，因阳而后行，如闭藏因于寒冽，而肃杀出乎风
霜。〕阳化气，阴成形，寒极生热，热极生寒；〔冬寒之极，将生春夏之热。夏热之极，将生秋冬之寒
。〕寒气生浊，热气生清。〔寒属阴，故生浊，热属阳，故生清。〕清气在下，则生飧泄；浊气在上
，则生 胀。〔清阳陷下，而不能升，故为飧泄，飧泄者完谷不化也。浊阴逆上而不能降，故为 胀，
胀者胸膈胀满也。〕清阳出上窍，浊阴出下窍；〔上有七窍，耳目口鼻也。下有二窍，前阴后
阴也。〕清阳发腠理，浊阴走五脏；清阳实四肢，浊阴归六腑。水为阴，火为阳，〔肾者水也，水中生
气，即真火也。心者火也，火中生液，即真水也。阴中有阳，阳中有阴，不可不知。〕阳为气，阴为味
，阳气出上窍，阴味出下窍。味浓者为阴；薄为阴之阳，气浓者为阳，薄为阳之阴。味浓则泄，薄则通；
气薄则发泄，浓则发热。壮火之气衰，少火之气壮；壮火食气，气食少火，壮火散气，少火生气。〔火者
阳气也，天非此火，不能生物，人非此火，不能有生。是以物生必本于阳，但阳和之火则生物。亢烈之火
则害物，故火太过则气反衰，火和平则气乃旺。壮火散气，故云食气，少火生气，故云食火。〕阴胜则阳
病，阳胜则阴病，阳胜则热，阴盛则寒，重寒则热，重热则寒。〔阴阳之变，水极则似火，火极则似水，
故假寒假热之症，不可不知。〕寒伤形，热伤气，〔寒则形消，热则气散。〕气伤痛，形伤肿，
〔气欲利，故伤之则痛，形有质，故伤之则肿。〕故先痛而后肿者，气伤形也；先肿而后痛者，形伤气
也。喜怒伤气，寒暑伤形。〔喜怒伤内，故伤气，寒暑伤外，故伤形。举喜怒言则悲忧恐同矣，举寒
暑言则燥湿风同矣。〕天不足西北，故西北方阴也，而人右耳目，不如左明也；地不满东南，故东南方
阳也，而人左手足，不如右强也。故俱感于邪，其在上则右甚，在下则左甚。平旦至日中，天之阳，阳
中之阳也；日中至黄昏，天之阳，阳中之阴也；合夜至鸡鸣，天之阴，阴中之阴也；鸡鸣至平旦，天之
阴，阴中之阳也。夫言人之阴阳，则外为阳，内为阴。言人身之阴阳，则背为阳，腹为阴。言人身脏腑之
阴阳，则脏者为阴，腑为阳。心肺脾肝肾五脏皆为阴，胆胃小肠大肠三焦膀胱六腑皆为阳。故背为阳，
阳中之阳，心也；背为阳，阳中之阴，肺也；腹为阴，阴中之至阴，脾也；腹为阴，阴中之阳，肝也；腹
为阴，阴中之阴，肾也。凡阴阳之要，阳密乃固。〔阴主内守，阳为外卫，阳密于外，则邪不能侵，而
阴乃得固于内。〕两者不合，若春无秋，〔偏于阳也。〕若冬无夏，〔偏于阴也。〕因而和之，是为圣
度。故阳强不能密，阴气乃绝；〔阳亢则阴气耗绝，〕阴平阳密，精神乃治。〔平，静也。密，固也。〕
阴精所奉，其人寿，阳精所降，其人夭。〔水旺则阴精充而奉上，土衰则阳精败而陷下。〕年四十而阴气
自半也，起居衰矣；〔四十以后，精气日衰，真阴减半。真阴即天一也，即坎水也，又谓元精。真阴既衰
，则真阳亦损，试观施而泄者，阴之精也，坚而热者，阳之气也，精去而阳痿，益征阴虚则无气之说矣
。浪用苦寒，伐阴为害。〕年五十，体重、而耳目不聪矣，〔精血渐衰之故，以肝受血
而能视。足受血而能步也。〕年六十阴痿，〔阳不主也。〕气大衰，九窍不利，〔阴气内亏也。〕
下虚上实，涕泣俱出矣。〔阴虚而阳无所归，气浮于上。〕故曰知之则强，不知则老。〔知、谓知养生
之道。〕
In ancient times, those who understood the Great Way modeled themselves on Yin and Yang, and conformed to the methods of technique and number. [This is the method of health preservation.] They had moderation in eating and drinking, regularity in rising and resting, and did not labor wantonly or excessively. Therefore, they could maintain the unity of form and spirit. [If the spirit departs, the form dies.] Thus, they completed their natural lifespan, living beyond a hundred years before passing away.
People of today treat wine as if it were water, make recklessness a habit, engage in sexual intercourse while intoxicated, exhaust their essence through desires, and dissipate their true Qi through overexertion. They do not know how to maintain fullness. [A state of fullness is prone to overturning.] They fail to regulate their spirit at appropriate times. [The spirit will inevitably scatter outward.] They pursue only momentary pleasure, going against the joy of life, and have no regularity in their daily routine. Consequently, they begin to decline before reaching fifty.
The sages of antiquity taught their people to avoid empty evils and thieving winds at the proper time. [This is the way to treat external pathogens.] By maintaining tranquility and emptiness, [Tranquility means being calm and indifferent to external things; emptiness means being unmoved internally.] the True Qi follows naturally, and the spirit remains guarded within. How could disease arise? [This is the way to treat internal disorders.] The sage does not treat disease after it has formed, but treats it before it forms; nor does he govern chaos after it has occurred, but prevents it before it happens. [This refers to the superior physician intervening at the earliest stage.] If one waits until disease is established to administer medicine, or until chaos has arisen to govern it, it would be like digging a well only when thirsty, or casting weapons only when battle begins. Would this not be too late?
Yin and Yang are the principles of Heaven and Earth, the guidelines for all things, the parents of change. [Although changes are numerous, they are all governed by Yin and Yang.] They are the beginning of birth and death. [The way of life and death is nothing other than Yin and Yang.] In treating disease, one must seek the root. [Disease manifestations are infinite, yet none exceed Yin and Yang. Knowing the origin of the disease allows one to target it directly for treatment.] Yin is quiet, Yang is active; Yin generates, Yang grows. [Yang cannot exist independently; it requires Yin to complete its formation, just as growth relies on harmonious Yang warmth, while nourishment depends on rain and dew.] Yang kills, Yin stores. [Yin cannot act alone; it moves because of Yang, just as storage occurs due to cold severity, while killing effects come from wind and frost.] Yang transforms into Qi, Yin forms into structure. Extreme cold generates heat, extreme heat generates cold. [When winter cold reaches its peak, spring and summer heat will arise. When summer heat reaches its peak, autumn and winter cold will arise.] Cold Qi generates turbidity, Hot Qi generates clarity. [Cold belongs to Yin, thus generating turbidity; Heat belongs to Yang, thus generating clarity.] If clear Yang sinks below, it causes undigested stool diarrhea (Sun Xie); if turbid Yin rises above, it causes distension. [If clear Yang sinks and fails to ascend, it leads to Sun Xie, which is diarrhea with undigested food. If turbid Yin rebels upward and fails to descend, it leads to distension, which is chest and diaphragm fullness.] Clear Yang exits through the upper orifices, turbid Yin exits through the lower orifices. [There are seven orifices above: ears, eyes, mouth, and nose. There are two orifices below: the anterior and posterior openings.] Clear Yang disperses into the interstices (Cou Li), turbid Yin flows into the Zang organs; Clear Yang fills the four limbs, turbid Yin returns to the Fu organs. Water is Yin, Fire is Yang. [The Kidney is Water; Qi generated within Water is True Fire. The Heart is Fire; fluid generated within Fire is True Water. Yin contains Yang, and Yang contains Yin; this must be known.] Yang corresponds to Qi, Yin corresponds to Flavor. Yang Qi exits through the upper orifices, Yin Flavor exits through the lower orifices. Strong flavors belong to Yin; thin flavors are Yang within Yin. Strong aromas belong to Yang; thin aromas are Yin within Yang. Strong flavors cause purgation, thin flavors promote circulation. Thin aromas induce sweating, strong aromas generate heat. Vigorous Fire causes Qi to decline, Mild Fire causes Qi to strengthen. Vigorous Fire consumes Qi, Qi nourishes Mild Fire. Vigorous Fire scatters Qi, Mild Fire generates Qi. [Fire is Yang Qi. Without this Fire, Heaven cannot produce life; without this Fire, humans cannot sustain life. Therefore, all things originate from Yang, but harmonious Fire produces life. Excessive Fire harms life; thus, excessive Fire causes Qi to decline, while balanced Fire makes Qi robust. Vigorous Fire scatters Qi, hence "consumes Qi"; Mild Fire generates Qi, hence "nourishes Qi."] If Yin prevails, Yang becomes diseased; if Yang prevails, Yin becomes diseased. Yang prevalence manifests as Heat, Yin prevalence manifests as Cold. Extreme Cold transforms into Heat, extreme Heat transforms into Cold. [Changes in Yin and Yang: extreme Water resembles Fire, extreme Fire resembles Water. Therefore, symptoms of false Cold and false Heat must be recognized.] Cold damages the Form, Heat damages the Qi. [Cold causes Form to waste, Heat causes Qi to scatter.] Damage to Qi causes pain, damage to Form causes swelling. [Qi should flow freely, so damage causes pain; Form has substance, so damage causes swelling.] Therefore, pain preceding swelling indicates Qi damaging Form; swelling preceding pain indicates Form damaging Qi. Joy and anger damage Qi, Cold and Heat damage Form. [Joy and anger damage the interior, thus damaging Qi; Cold and Heat damage the exterior, thus damaging Form. Mentioning Joy and Anger implies Sorrow, Worry, and Fear are similar; mentioning Cold and Heat implies Dryness, Dampness, and Wind are similar.] Heaven's Qi is insufficient in the Northwest, so the Northwest belongs to Yin; consequently, the right ear and eye are less acute than the left. Earth's Qi is incomplete in the Southeast, so the Southeast belongs to Yang; consequently, the left hand and foot are weaker than the right. Therefore, if both sides are affected by pathogenic factors, lesions above affect the right more severely, and lesions below affect the left more severely.
From dawn to noon is Heaven's Yang, specifically Yang within Yang. From noon to dusk is Heaven's Yang, specifically Yin within Yang. From nightfall to midnight is Heaven's Yin, specifically Yin within Yin. From midnight to dawn is Heaven's Yin, specifically Yang within Yin. Regarding human Yin and Yang, the exterior is Yang, the interior is Yin. Regarding the body's Yin and Yang, the back is Yang, the abdomen is Yin. Regarding the Zang-Fu organs' Yin and Yang, the Zang organs are Yin, the Fu organs are Yang. The Heart, Lungs, Spleen, Liver, and Kidneys (five Zang) are all Yin. The Gallbladder, Stomach, Small Intestine, Large Intestine, San Jiao, and Bladder (six Fu) are all Yang. Thus, the back is Yang; among Yang, the Heart is Yang within Yang. The back is Yang; among Yang, the Lung is Yin within Yang. The abdomen is Yin; among Yin, the Spleen is Ultimate Yin. The abdomen is Yin; among Yin, the Liver is Yang within Yin. The abdomen is Yin; among Yin, the Kidney is Yin within Yin. The key to Yin and Yang lies in Yang being dense and secure. [Yin guards the interior, Yang guards the exterior. If Yang is dense externally, pathogens cannot invade, and Yin can remain secure internally.] If these two do not harmonize, it is like having Spring without Autumn. [Bias toward Yang.] It is like having Winter without Summer. [Bias toward Yin.] Harmonizing them accordingly constitutes the standard of the sage. Therefore, if Yang is excessive and cannot be dense, Yin Qi will perish. [Yang hyperactivity depletes Yin Qi.] If Yin is peaceful and Yang is dense, Spirit and Qi will be regulated. [Peaceful means calm; dense means secure.] Where Yin Essence is abundant and supported, longevity is achieved; where Yang Essence declines and sinks, premature death occurs. [When Water is prosperous, Yin Essence is sufficient and supports upward movement; when Earth is deficient, Yang Essence decays and sinks downward.] At forty, Yin Qi naturally halves, and daily vitality declines. [After forty, Essence and Qi gradually weaken, and True Yin halves. True Yin is the Water of Tian Yi, Kan Water, also called Primordial Essence. As True Yin declines, True Yang is also damaged. Consider that ejaculation releases Yin Essence, while erection and heat represent Yang Qi. Loss of Essence leads to impotence, confirming the theory that Yin deficiency results in lack of Qi. Indiscriminate use of bitter-cold herbs harms Yin.] At fifty, the body feels heavy, and hearing and vision deteriorate. [This is due to gradual decline of Essence and Blood; the Liver receives blood to enable sight, and the feet receive blood to enable walking.] At sixty, impotence occurs. [Yang no longer dominates function.] Qi significantly declines, and the nine orifices become obstructed. [Internal deficiency of Yin Qi.] Lower deficiency and upper excess result in running nose and tears. [Yin deficiency leaves Yang without attachment, causing Qi to float upward.] Therefore, it is said: those who understand [health preservation] become strong, those who do not age prematurely. [Understanding refers to knowing the Dao of health preservation.]