According to traditional medicine, the kidney is the innate foundation, the key to storing essence, the source of fertility, the main bone marrow, and the enlightenment to the ear. With sufficient kidney essence, people are full of energy, strong bones, strong teeth and smart eyes and ears, thus maintaining normal life activities of the human body. On May 8, when he reached 40 years old, signs of aging appeared repeatedly due to the deficiency of kidney qi and kidney essence. Therefore, Neijing said: "Exhaustion of essence and deficiency of kidney qi", emphasizing the role of kidney essence in the aging process. It is believed that premature aging is due to "exhausting its essence, consuming its truth and hurting its spirit". In Qing Dynasty, Ye proposed that "the old child will lose the next yuan first", which is consistent with the aging manifestations observed by modern people, such as weak waist and knees, sexual dysfunction, tooth loss and hearing loss.

There are many reasons for kidney deficiency: in addition to congenital endowment, it is also related to sexual immorality and overwork. Therefore, Su Wen said: "Take wine as the pulp, be unscrupulous, get drunk before you rest, try your best to exhaust its essence, dissipate its truth, never know how full it is, and always resist God." "Half a hundred will fail." Zhang Jingyue emphasized in Jing Lei: "Therefore, people who are good at keeping in good health must cherish their own essence. Essence is full of gas, full of gas is full of gas, full of gas is healthy, and good health is less sick. Being old and strong depends on kidney essence ... you can live forever and not shake your essence. "

Since ancient times, there has been the idea that housework does not lead to longevity. Although extravagant emperors and rich people have rich living conditions, they have eaten all kinds of delicacies and enjoyed all the splendor, but few people can enjoy their old age and live a long life. Therefore, a strong school of cherishing essence, preserving essence and solidifying essence has been formed. Most of the effective anti-aging drugs used in past dynasties are mainly tonifying kidney and replenishing essence. Wang Zhongyang, a health care scientist in Yuan Dynasty, also said: "In ancient times, men got married at the age of 30 and women got married at the age of 20. The 30-year-old man was discharged on the 8th, the 40-year-old man was discharged on the 6th/kloc, and the 50-year-old man was discharged on the 2nd/kloc/0/day. "People are earnestly warned that in order to keep healthy and prolong life, they should marry late and abstain from sex.