黄帝曰∶夫自古通天者生之本，本于阴阳。天地之间，六合之内，其气九州九窍、五脏、十二节，皆通
乎天气。其生五，其气三，数犯此者，则邪气伤人，
此寿命之本也。苍天之气，清净则志意治，顺之则阳气固，虽有贼邪，弗能害也，此因时之序。故圣人传精神，
服天气，而通神明。失之则内闭九窍，外壅肌肉，卫气散解，此谓自伤，气之削也。阳气者若天与日，失其所
则折寿而不彰，故天运当以日光
明。是故阳因而上，卫外者也。因于寒，欲如运枢，起居如惊，神气乃浮。因于暑，汗，烦则喘喝，静则多言，
体若燔炭，汗出而散。因于湿，首如裹，湿热不攘，大筋 短，小筋弛长， 短为拘，弛长为痿。因于气，为
肿，四维相代，阳气乃竭。阳气者，烦劳则张，精绝辟积，于夏使人煎厥。目盲不可以视，耳
闭不可以听，溃溃乎若坏都，汨汨乎不可止。阳气者，大怒则形气绝，而血菀于上，使人薄厥。有伤于筋，纵，
其若不容，汗出偏沮，使人偏枯。汗出见湿，乃生痤痱。高粱之变，足生大丁，受如持虚。劳汗当风，寒薄
为，郁乃痤。阳气者，精则养神，
柔则养筋。开阖不得，寒气从之，乃生大偻。陷脉为 ，留连肉腠。俞气化薄，传为善畏，及为惊骇。营气
不从，逆于肉理，乃生痈肿。魄汗未尽，形弱而气烁，穴俞以闭，发为风疟。故风者，百病之始也，清静则肉
腠闭拒，虽有大风苛毒，弗之能害，此因时之序也。故病久则传化，上下不并，良医弗为。故阳
蓄积病死，而阳气当隔，隔者当泻，不亟正治，粗乃败之。故阳气者，一日而主外，平旦人气生，日中而阳气
隆，日西而阳气已虚，气门乃闭。是故暮而收拒，无扰筋骨，无见雾露，反此三时，形乃困薄。
岐伯曰∶阴者，藏精而起亟也；阳者，卫外而为固也。阴不胜其阳，则脉流薄疾，并乃狂。阳不胜
其阴，则五脏气争，九窍不通。是以圣人陈阴阳，筋脉和同，骨髓坚固，气血皆从。如是则内外调和，邪不能
害，耳目聪明，气立如故。风客淫气，精乃亡，邪伤肝也。因而饱食，筋脉横解，肠 为痔。因而大饮，则
气逆。因而强力，肾气乃伤，高骨乃坏。凡阴阳之要，阳密乃固。两者不和，若春无秋，若冬
无夏，因而和之，是谓圣度。故阳强不能密，阴气乃绝，阴平阳秘，精神乃治，阴阳离决，精气乃绝，因于露
风，乃生寒热。是以春伤于风，邪气留连，乃为洞泄。夏伤于暑，秋为 疟。秋伤于湿，上逆而咳，发为痿厥。
冬伤于寒，春必温病。四时之气，更伤五脏。阴之所生，本在五味，阴之五宫，
伤在五味。是故味过于酸，肝气以津，脾气乃绝。味过于咸，大骨气劳，短肌，心气抑。味过于甘，心气喘满，
色黑，肾气不衡。味过于苦，脾气不濡，胃气乃浓。味过于辛，筋脉沮弛，精神乃央。是故谨和五味，骨正筋
柔，气血以流，腠理以密，如是则骨气以精，谨道如法，长有天命。
Huangdi said: Since ancient times, the connection between humans and nature is the root of life, which originates from Yin and Yang. Within the heaven and earth, inside the six directions, the Qi connects with the nine provinces, nine orifices, five zang organs, and twelve joints, all communicating with the heavenly Qi. Life is generated based on the Five Elements, and its Qi operates in three aspects (Heaven, Earth, and Humanity). If one frequently violates these principles, pathogenic Qi will harm the body; this is the foundation of longevity.
The Qi of the blue sky, when pure and tranquil, keeps the will and mind regulated. Following it consolidates the Wei Qi (Defensive Qi); even if harmful pathogens attack, they cannot cause injury. This is due to following the sequence of seasons. Therefore, the sages conserve their spirit, assimilate the heavenly Qi, and communicate with divine clarity. Failure to do so results in the internal blockage of the nine orifices, external stagnation of muscles, and the dispersion and dissolution of Wei Qi (Defensive Qi). This is called self-injury, leading to the depletion of Qi.
Yang Qi is like the sky and the sun. If it loses its proper position, lifespan is shortened and brilliance is obscured; thus, the movement of heaven relies on sunlight for illumination. Therefore, Yang Qi resides above and guards the exterior. When affected by Cold, Yang Qi should move flexibly like a door pivot; if daily activities are disturbing and restless, Shen Qi (Spiritual Qi) becomes floating. When affected by Summerheat, sweating occurs; if vexed, there is panting and loud breathing; if quiet, there is excessive talking. The body feels like burning charcoal, and the heat dissipates upon sweating. When affected by Dampness, the head feels as if wrapped; if Damp-Heat is not cleared, the large tendons shorten and the small tendons elongate. Shortening leads to spasms (Ju Luan), while elongation leads to flaccidity (Wei Zheng). When affected by Wind Qi, swelling occurs; if the four extremities alternate in damage, Yang Qi is exhausted.
When Yang Qi is subjected to excessive fatigue and labor, it hyperactivates. With repeated accumulation of essence depletion, it causes Jian Jue (Frying Collapse) in summer. Symptoms include blindness preventing vision and deafness preventing hearing. The condition is critical, resembling a collapsing dam, with torrents unstoppable. When Yang Qi is triggered by great anger, form and Qi become severed, and blood stagnates at the upper part, causing Bo Jue (Thin Collapse). If tendons are injured, they become lax, rendering limbs immobile. Hemihidrosis (sweating on only one side) leads to hemiplegia (Pian Gu). Sweating followed by exposure to dampness generates acne and miliaria (Cuo Fei). Excessive consumption of rich food and wine can lead to large carbuncles; pathogenic invasion is as easy as holding an empty vessel. Labor-induced sweating exposed to wind, where cold compresses the skin, forms acne (Za); stagnation leads to pustules (Cuo).
Yang Qi’s refined aspect nourishes the Shen (Spirit), and its soft aspect nourishes the tendons. If opening and closing functions fail, Cold Qi follows and enters, causing severe kyphosis (Da Lou). Pathogens sinking into meridians linger in muscle intervals. Acupoint Qi transforms thinly, transmitting fear and惊骇 (startle/terror). Ying Qi (Nutritive Qi) does not flow smoothly, reversing in muscle textures, generating carbuncles and swellings. If Po Han (corporeal sweat) is not fully expelled, the form weakens and Qi is scorched; acupoints close, developing Wind Malaria (Feng Nue). Thus, Wind is the beginning of all diseases. If one remains tranquil, muscle intervals close and resist; even strong winds and severe toxins cannot harm. This follows the seasonal order. However, prolonged illness leads to transformation and transmission; if Upper and Lower Qi do not connect, even good physicians cannot help.
Yang Qi accumulation leads to death when Yang Qi is blocked. Blockage requires purging. Without prompt correct treatment, incompetent doctors will ruin the patient. Yang Qi governs the exterior during the day. At dawn, human Qi arises; at noon, Yang Qi is peak; at sunset, Yang Qi is deficient, and the Qi Gates (pores) close. Therefore, in the evening, one should gather and resist, not disturb sinews and bones, and avoid fog and dew. Reversing these three times leads to physical exhaustion.
Qibo said: Yin stores essence and rises urgently to support Yang; Yang guards the exterior and maintains solidity. If Yin cannot overcome Yang, pulse flow becomes rapid and forceful, leading to mania (Kuang). If Yang cannot overcome Yin, the Qi of the five Zang organs contends, and the nine orifices become blocked. Thus, sages arrange Yin and Yang, harmonizing sinews and vessels, solidifying marrow, and ensuring smooth Qi and Blood. In this state, interior and exterior are harmonious, pathogens cannot harm, ears and eyes are clear, and Qi stands as usual.
Wind pathogens invading and disrupting Qi cause essence loss and liver injury. After overeating, sinews and vessels relax transversely, and intestinal stasis causes hemorrhoids. After drinking excessively, Qi rebels upward. After strenuous sexual activity, Kidney Qi is injured, and high bones (vertebrae) deteriorate. The key to Yin and Yang is that dense Yang ensures solidity. If the two are disharmonious, it is like spring without autumn or winter without summer. Harmonizing them according to principle is called the sage's standard. If Yang is strong but not dense, Yin Qi perishes. If Yin is peaceful and Yang is secret, Spirit is governed. If Yin and Yang separate and decide, Essence and Qi perish. Exposure to wind generates cold and heat disorders.
Spring wind injury leaves lingering pathogens, causing severe diarrhea (Dong Xie). Summer heat injury manifests as malaria in autumn. Autumn dampness injury causes rebellious Qi, coughing, and flaccidity-cold (Wei Jue). Winter cold injury leads to warm diseases in spring. The Qi of the four seasons alternately injures the five Zang organs.
Yin is generated from the Five Flavors; the five Yin palaces are damaged by the Five Flavors. Excessive sour flavor causes Liver Qi to overflow and Spleen Qi to cease. Excessive salty flavor labors the large bones, shortens muscles, and suppresses Heart Qi. Excessive sweet flavor causes Heart Qi to pant and distend, black complexion, and unbalanced Kidney Qi. Excessive bitter flavor makes Spleen Qi non-moist and Stomach Qi thick. Excessive pungent flavor causes sinews and vessels to slacken and damages Spirit. Therefore, carefully harmonize the Five Flavors to keep bones straight, sinews flexible, Qi and Blood flowing, and interstices dense. In this way, bone Qi becomes refined. Following the Dao and methods ensures a long lifespan.