How external factors and emotions affect health:
Four Pathogens: Cold stagnates energy; heat causes breathing issues and delirium; wetness weights the head and warps muscles; sluggish qi causes swelling.
Emotions & Habits: Overwork dries vital essence; rage causes fainting and paralysis. Greasy food and sweating in wind/humidity trigger severe skin sores.
Universal Connection: Human life, organs, and joints are inherently linked to nature's cycles and Yin-Yang. Harmony with these rhythms ensures health, while violation causes internal blockages and disease.
Primacy of Yang: Yang energy is like the sun; it moves outward to shield the body. If compromised, vitality fades and life is cut short.
Nature's harmony maintains life; deviations cause disease and decay. The wise align with the seasons—nourishing Yang in spring/summer and Yin in autumn/winter—to prevent illness. True mastery lies in "treating before disease arises." Curing a sickness after it occurs is as futile as digging a well only when one is already thirsty.
The Huangdi Neijing details the "Way of Nurturing Life" across four seasons. Spring fosters growth, summer promotes development, autumn focuses on harvesting, and winter demands conservation. Living against these natural cycles harms the corresponding organs—liver, heart, lungs, or kidneys—causing illness in the subsequent season.
Exceptions to the aging cycle exist:
Extraordinary Vitality: Some elderly can have children if their Qi flows freely and Shenqi remains abundant, though their reproductive essence still depletes eventually.
Masters of Tao: Those practicing Taoism can reverse aging, preserve their bodies, and remain fertile regardless of age.
human life follows aging cycles driven by Qi and Tiangui:
Women (7-year cycle): Fertile at 14 (2×7) as Tiangui arrives; peaks at 28 (4×7); loses fertility at 49 (7×7) when Tiangui depletes.
Men (8-year cycle): Fertile at 16 (2×8); peaks at 32 (4×8); loses fertility at 64 (8×8) as vital organs and Tiangui fail.
The Huangdi Neijing contrasts ancient longevity with modern decline. The Yellow Emperor asks why ancients lived vibrantly past a hundred, while modern people weaken by fifty. Qibo explains that ancients followed the Dao, balancing Yin and Yang, eating moderately, and sleeping regularly to unify body and spirit. Moderns drain their energy through alcohol and reckless desires. True health comes from inner tranquillity.