黄帝问曰∶气之盛衰，可得闻乎？岐伯对曰∶人年十岁（一作十六），五脏始定，血气已
通，其气在下，故好走。二十岁，血气始盛，肌肉方长，故好趋。三十岁，五脏大定，肌肉
坚固，血脉盛满，故好步。四十岁，五脏六腑十二经脉皆大盛平定，腠理始开，荣华剥落
，鬓发颁白，平盛不摇，故好坐。五十岁，肝气始衰，肝叶始薄，胆汁始减，目始不明。六
十岁，心气始衰，乃善忧悲，血气懈堕，故好卧。七十岁，脾气虚，皮肤始枯，故四肢不举
。八十岁，肺气衰，魂魄离散，故言善误。九十岁，肾气焦，脏乃萎枯，经脉空虚。至百岁
，五脏皆虚，神气皆去，形骸独居而终尽矣。
女子七岁，肾气盛，齿更发长。二七天水至（《素问》作天癸至），任脉通，太冲脉盛，
月事以时下，故有子。三七肾气平均，故真牙生而长极。四七筋骨坚，发长极，身体盛壮。
五七阳明脉衰，面皆焦，发始白。七七任脉虚，太冲（一作任）脉衰少，天水竭，地道不通
，故形坏而无子耳。
丈夫八岁，肾气实，发长齿更。二八肾气盛，天水至而精气溢泻，阴阳和，故能有子
。三八肾气平均，筋骨劲强，故真牙生而长极。四八筋骨隆盛，肌肉满壮。五八肾气衰，发
堕齿槁。六八阳气衰于上，面焦，鬓发颁白。七八肝气衰，筋不能动，天水竭，精少，肾气
衰，形体皆极，八八则齿发去。肾者主水，受五脏六腑之精而藏之，故五脏盛乃能泻。今五
脏皆衰，筋懈骨堕，天水尽矣。故发鬓白，体重，行步不正而无子耳。
黄帝问道：人体之气的盛衰变化，可以讲给我听吗？岐伯回答说：人到了十岁（另一种说法是十六岁），五脏六腑的功能开始稳定，血气已经通畅，气机主要运行于下部，所以喜欢奔跑。二十岁时，血气开始旺盛，肌肉正在生长，所以喜欢快走。三十岁时，五脏完全稳定，肌肉坚固，血脉充盈，所以喜欢步行。四十岁时，五脏六腑及十二经脉的气血都达到盛大且平稳的状态，腠理开始疏松，容颜开始衰退，两鬓头发斑白，气血虽盛但不再剧烈波动，所以喜欢静坐。五十岁时，肝气开始衰退，肝脏组织变薄，胆汁分泌减少，眼睛开始看不清楚。六十岁时，心气开始衰退，容易忧愁悲伤，血气懈怠松弛，所以喜欢躺卧。七十岁时，脾气虚弱，皮肤开始干枯，所以四肢无力抬举。八十岁时，肺气衰退，魂魄离散，所以说话容易出错。九十岁时，肾气枯竭，脏腑萎缩枯槁，经脉空虚。到了百岁，五脏精气全部虚竭，神气离去，只剩躯壳独自存在而生命终结。
女子七岁时，肾气充盛，牙齿更换，头发生长。十四岁时，天癸（促进生殖机能成熟的物质）到来，任脉通畅，太冲脉旺盛，月经按时来潮，所以能够生育。二十一岁时，肾气平和均匀，智齿长出，身体长到最高限度。二十八岁时，筋骨坚实，头发长到极点，身体处于最壮盛的时期。三十五岁时，阳明经的气血开始衰退，面部颜色焦枯，头发开始变白。四十九岁时，任脉虚弱，太冲脉衰少，天癸枯竭，月经停止，所以形体衰老而不能生育。
男子八岁时，肾气充实，头发生长，牙齿更换。十六岁时，肾气旺盛，天癸到来，精气满溢而泄出，阴阳调和，所以能够生育。二十四岁时，肾气平和均匀，筋骨强劲有力，智齿长出，身体长到最高限度。三十二岁时，筋骨隆盛，肌肉丰满健壮。四十岁时，肾气开始衰退，头发脱落，牙齿枯槁。四十八岁时，阳气在上部衰退，面部焦枯，两鬓头发斑白。五十六岁时，肝气衰退，筋脉活动不灵活，天癸枯竭，精液减少，肾气衰弱，形体极度疲惫。六十四岁时，牙齿和头发脱落。肾主水液代谢，接受并贮藏五脏六腑的精微物质，所以只有五脏精气充盛，才能向外排泄生殖之精。现在五脏都已衰退，筋脉懈怠，骨骼软弱，天癸耗尽。所以出现两鬓斑白，身体沉重，行走不稳而不能生育的情况。
Huangdi asked, saying: May I inquire about the flourishing and declining states of Qi? Qibo replied: At ten years of age (in another version, sixteen), the Zang organs begin to stabilize, Blood and Qi are already flowing through the meridians, and its Qi is located in the lower part; therefore, one enjoys running. At twenty years of age, Blood and Qi begin to flourish, muscles are growing, therefore one enjoys walking quickly. At thirty years of age, the Zang organs are fully stabilized, muscles are firm, and blood vessels are full; therefore, one enjoys walking steadily. At forty years of age, the Qi of the Zang and Fu organs and the twelve regular meridians reaches a peak and stabilizes, the interstices (Couli) begin to open, luster fades, and the hair on the temples turns gray; although abundant, it does not fluctuate wildly, therefore one enjoys sitting. At fifty years of age, Liver Qi begins to decline, the liver tissue becomes thinner, bile secretion decreases, and vision begins to blur. At sixty years of age, Heart Qi begins to decline, leading to frequent sorrow and grief; Blood and Qi become slack and lax, therefore one enjoys lying down. At seventy years of age, Spleen Qi is deficient, the skin begins to wither, therefore the four limbs cannot be lifted. At eighty years of age, Lung Qi declines, the Hun and Po spirits scatter, therefore speech is prone to errors. At ninety years of age, Kidney Qi is exhausted, the Zang organs wither and dry up, and the meridians become empty. Upon reaching one hundred years of age, all five Zang organs are deficient, Shen Qi departs, and only the physical form remains alone until death.
For females, at seven years of age, Kidney Qi flourishes, teeth change, and hair grows. At fourteen years of age (referred to as Tian Gui arriving in *Suwen*), the Ren Mai (Conception Vessel) becomes unobstructed, and the Chong Mai (Penetrating Vessel) flourishes; menstruation arrives on time, therefore conception is possible. At twenty-one years of age, Kidney Qi is balanced and even, wisdom teeth emerge, and the body reaches its maximum height. At twenty-eight years of age, sinews and bones are strong, hair reaches its maximum length, and the body is in its prime. At thirty-five years of age, the Yangming meridians decline, the face becomes sallow, and hair begins to turn white. At forty-nine years of age, the Ren Mai becomes deficient, the Chong Mai (or Ren Mai in some versions) declines, Tian Gui is exhausted, and the menstrual pathway is blocked; therefore, the body deteriorates and fertility ceases.
For males, at eight years of age, Kidney Qi is substantial, hair grows, and teeth change. At sixteen years of age, Kidney Qi flourishes, Tian Gui arrives, essence overflows and is discharged; Yin and Yang harmonize, therefore conception is possible. At twenty-four years of age, Kidney Qi is balanced and even, sinews and bones are vigorous, wisdom teeth emerge, and the body reaches its maximum height. At thirty-two years of age, sinews and bones are robust, and muscles are full and strong. At forty years of age, Kidney Qi begins to decline, hair falls out, and teeth become brittle. At forty-eight years of age, Yang Qi declines in the upper body, the face becomes sallow, and the hair on the temples turns gray. At fifty-six years of age, Liver Qi declines, sinews cannot move freely, Tian Gui is exhausted, essence is scant, Kidney Qi weakens, and the physical form reaches extreme fatigue. At sixty-four years of age, teeth and hair fall out. The Kidneys govern water metabolism and receive and store the essence of the five Zang and six Fu organs; therefore, only when the five Zang organs are flourishing can they excrete reproductive essence. Now that all five Zang organs have declined, sinews are lax, bones are weak, and Tian Gui is exhausted. Thus, there is graying of the hair and beard, heaviness of the body, unsteady gait, and infertility.