The Yellow Emperor’s Inquiry: Mastering Yin and Yang for Health

The Yellow Emperor stated: “Yin and Yang represent the universal principles of the cosmos, the guidelines for all phenomena, the source of all transformations, the foundation of life and death, and the mainstay governing the existence of all things. Therefore, treating diseases must adhere to the fundamental principles of Yin and Yang. Consider the analogy of nature: pure Yang energy rises to form the heavens, while turbid Yin energy descends to form the earth. Yin is tranquil and passive, while Yang is dynamic and active; Yang promotes growth, and Yin fosters development; Yang governs contraction, and Yin governs preservation; Yang can transform into energy, and Yin can form physical structures. Extreme cold begets heat, and extreme heat begets cold; cold generates turbid Yin, and heat generates pure Yang; when pure Yang energy remains below and does not ascend, it causes diarrhea; when turbid Yin energy remains above and does not descend, it causes chest congestion. These are the normal and abnormal transformations of Yin and Yang, which in turn distinguish between favorable and adverse conditions in disease.”

“Thus, in nature, the clear Yang energy rises to become the heavens, while the turbid Yin energy descends to become the earth. Earthly vapors ascend to form clouds, and heavenly condensation descends as rain; rain is the transformation of ascending earthly vapors, while clouds are formed from evaporating heavenly vapors. (Similarly, in the human body,) pure Yang energy exits through the upper orifices, while turbid Yin energy exits through the lower orifices; pure Yang energy disperses through the pores, while turbid Yin energy accumulates in the internal organs; pure Yang energy fills the limbs, while turbid Yin energy flows through the six Fu organs.”

“Water, which flows downward, is Yin; fire, which rises upward, is Yang. Heaven supplies people with the five Yang energies (cold, heat, warmth, coolness, and neutrality), while earth supplies people with the five Yin flavors (sour, bitter, sweet, spicy, and salty). The five flavors nourish the body through the stomach, manifesting human essence externally. Human essence is nurtured by the quintessence of grains, which in turn is derived from the five flavors. When the quintessence of grains nourishes human essence, it supports the body; when human essence manifests outwardly, it nourishes the body. Imbalanced diet and excessive activities can deplete essence, harming the body, as the quintessence of grains may be damaged by imbalanced flavors.”

“Flavors, being Yin, descend to the lower orifices, while Qi, being Yang, ascends to the upper orifices. Thick flavors belong to Yin within Yin, while thin flavors belong to Yin within Yang; thick Qi belongs to Yang within Yang, while thin Qi belongs to Yang within Yin. Thick flavors have a purging effect, while thin flavors have a facilitating effect. Thin Qi can disperse outward, while thick Qi can help Yang generate heat. Excessive Yang Qi weakens true Qi, while normal Yang Qi strengthens true Qi; overly exuberant Yang Qi harms true Qi, which relies on normal Yang Qi for nourishment; overly exuberant Yang Qi dissipates true Qi, while normal Yang Qi enhances true Qi. Spicy and sweet flavors with dispersing properties belong to Yang; sour and bitter flavors with purging properties belong to Yin.”

“When Yin is excessive, Yang is damaged, causing disease; when Yang is excessive, Yin is depleted, causing disease. Excessive Yang causes heat-related symptoms, while excessive Yin causes cold-related symptoms. Extreme cold manifests as heat, while extreme heat manifests as cold. Cold injures the body, while heat injures the Qi. Injured Qi causes bodily pain, which leads to swelling. Pain followed by swelling indicates Qi injury preceding bodily injury; swelling followed by pain indicates bodily injury preceding Qi injury. Excessive wind causes convulsions; excessive heat causes redness and swelling; excessive dryness causes withering; excessive cold causes swelling; excessive dampness causes diarrhea.”

“Nature undergoes seasonal transitions: spring, summer, (late summer), autumn, and winter, with the five elements (wood, fire, earth, metal, and water) and corresponding climatic influences (wind, heat, dryness, dampness, and cold), which affect all things, forming the cycles of growth, development, (transformation), harvest, and storage. Humans possess five Zang organs (liver, heart, spleen, lungs, and kidneys), which give rise to five emotions (joy, anger, sorrow, anxiety, and fear). Emotional changes can harm Qi, while external invasions of cold and heat can harm the body. Sudden anger damages Yin, while sudden joy damages Yang. Rebellious Qi ascending fills the meridians, causing the spirit to float away from the body. Uncontrolled emotions and poor adaptation to climate compromise life. Extreme Yin transforms into Yang, and extreme Yang transforms into Yin. Hence, ‘cold injuries in winter cause febrile diseases in spring; wind injuries in spring cause diarrhea in summer; heat injuries in summer cause malaria in autumn; dampness injuries in autumn cause coughing in winter.’”

“The Yellow Emperor asked: ‘I’ve heard that ancient sages studied human anatomy, distinguishing the Yin and Yang of the organs; they examined the connections of the meridians, classifying the twelve meridians into six pairs of Yin and Yang, and charted their routes; each meridian point had precise locations and names; muscles and bones had distinct origins and insertions; the surface and superficial collaterals of the meridian system were clearly organized, despite their varying directions; the seasonal changes of Yin and Yang followed specific patterns; the external environment corresponded to the internal organs and meridians in a harmonious relationship. Are these statements accurate?’”

“Qi Bo replied: ‘The east corresponds to spring, with Yang rising and warm winds nurturing, encouraging plant growth, producing sour flavors, which nourish the liver, benefiting the tendons, making the heart blood abundant, and connecting liver Qi with the eyes. The five elements are mysterious and infinite in the heavens, represent natural principles in humans, and generate all things on earth, producing the five flavors, enabling humans to understand nature and gain wisdom. The eastern changes in the five elements manifest as wind in the heavens, wood on earth, tendons in the human body, and the liver among the organs; they correlate with the color blue-green, the Jiao note, the call sound, grasping in illness, the eyes among the orifices, the sour flavor, and anger among emotions. Anger damages the liver, but sorrow mitigates anger; wind injures the tendons, but dryness mitigates wind; excessive sourness injures tendons, but spiciness mitigates sourness.”

“The south corresponds to summer, with exuberant Yang generating heat, which produces fire, creating bitter flavors, nourishing the heart, which generates blood, nourishing the spleen, and connecting heart Qi with the tongue. The southern changes in the five elements manifest as heat in the heavens, fire on earth, blood vessels in the human body, and the heart among the organs; they correlate with the color red, the Zhi note, laughter in sound, stuttering in illness, the tongue among the orifices, the bitter flavor, and joy among emotions. Joy damages the heart, but fear mitigates joy; heat injures Qi, but cold mitigates heat; bitterness damages Qi, but saltiness mitigates bitterness.”

“The center corresponds to late summer, with late summer generating dampness, corresponding to earth, which creates sweet flavors, nourishing the spleen, which nourishes muscles, enhancing lung function, and connecting spleen Qi with the mouth. The central changes in the five elements manifest as dampness in the heavens, earth on the ground, muscles in the human body, and the spleen among the organs; they correlate with the color yellow, the Gong note, singing in sound, retching in illness, the mouth among the orifices, the sweet flavor, and thought among emotions. Excessive thinking harms the spleen, but anger mitigates thinking; dampness injures muscles, but wind mitigates dampness; sweetness damages muscles, but sourness mitigates sweetness.”

“The west corresponds to autumn, with brisk weather generating dryness, corresponding to metal, which creates spicy flavors, nourishing the lungs, which nourish the skin and hair, enhancing kidney function, and connecting lung Qi with the nose. The western changes in the five elements manifest as dryness in the heavens, metal on earth, skin and hair in the human body, and the lungs among the organs; they correlate with the color white, the Shang note, crying in sound, coughing in illness, the nose among the orifices, the spicy flavor, and sorrow among emotions. Sorrow damages the lungs, but joy mitigates sorrow; heat injures the skin and hair, but cold mitigates heat; spiciness damages the skin and hair, but bitterness mitigates spiciness.”

The north corresponds to winter, with cold weather generating cold, corresponding to water, which creates salty flavors, nourishing the kidneys, which nourish the bones, enhancing liver function, and connecting kidney Qi with the ears. The northern changes in the five elements manifest as cold in the heavens, water on earth, bones in the human body, and the kidneys among the organs; they correlate with the color black, the Yu note, groaning in sound, shivering in illness, the ears among the orifices, the salty flavor, and fear among emotions. Fear damages the kidneys, but thought mitigates fear; cold injures the bones, but dampness