The term “return to old age” is from “The Seven Signatures of the Cloud”, Volume 60: “daily serving a thousand swallows, not enough for more, return to old age, gradually from this carry on”; its description is also found in Han Shi You “urgent on the chapter”: “long happiness Wuji old again Ding The description is also found in Han Shi You’s “The Book of Urgency”: “Changle Wuji’s old age returns to Ding” and “The Book of the Old Tang Dynasty”: “It can heal the disease of impotence, weakness and weight, and return to the old age. It means reversing aging and reverting to childhood; describing an elderly person who has regained the health or spirit of youth, and also describing an elderly person who has regained youth and vitality and is unusually energetic. In clinical work, some patients need long-term acupuncture treatment because of other diseases, but after a period of acupuncture, found that the original has been silver-white hair, from the hairline began to darken; originally old flowering eyes, recently felt brighter; the previous section is still sore and shaky teeth, recently felt solid; also some patients whose hair on the top of the head has been lost, recently found that the growth of new hair. Are these not signs of our rejuvenation? It is the dream of many people to return to their energetic and youthful days after entering the old age when their body functions are gradually declining. Can acupuncture really bring us back to our youth? But how can acupuncture cause these “rejuvenation” phenomena while treating the primary disease? We know that acupuncture is based on the theory of meridians and acupoints, and when treating diseases, we have to analyze the evidence and take points according to the patient’s condition. In Chinese medicine, the kidney has an important position as the “root of the innate nature”. In the “Emperor’s Classic of Internal Medicine, Su Wen”, there is an account of the development and aging of the kidney qi in men and women as they grow older, as well as the changes of the kidney qi in the course of life, and the different physiological states of birth, growth, strength, aging, and aging. Among them, it is mentioned that “when the kidney is strong, the teeth are longer” and “when the kidney is weak, the form is extreme, then the teeth and hair go”. Hair for the kidney, the kidney is the main bone, teeth for the rest of the bone; patients with sufficient kidney essence, the teeth are firm hair; if the kidney essence is not enough, there will be hair whitening, loose teeth, and even fall off. With the growth of age, the loss of kidney essence, most of the middle-aged and elderly people will appear kidney deficiency evidence, we will also be in clinical treatment will be used to fill the corresponding method of kidney essence; long-term treatment, such as the patient kidney essence to nurture, then the hair back to the u teeth also firm. Many people who know Chinese medicine know that eye diseases and liver meridian is very close, liver blood nourishes the eyes, then the eyes can see, liver blood is not enough, then the eyes are astringent unknown. Why can the kidney also brighten the eyes? I do not know that the “Nei Jing” already has the theory of “liver and kidney homologation”, which is also known as the same source of B and K. There are three meanings: 1. There are three meanings: 1, liver collects blood, kidney collects essence, essence and blood are produced together, so liver and kidney yin nourish each other, liver and kidney are born together; 2, liver and kidney both contain phase fire, phase fire originates from the vital gate; 3, liver and kidney deficiency is closely related to each other, mutual restraint, treatment mostly take into account the two organs. This indicates that although there are differences in the structure and functions of the liver and kidney, their origins are the same and their physiopathology is closely related. When the kidney essence is replenished, the liver meridian is also enriched, and the darkness of the eyes will be improved. Is there a reasonable explanation for these phenomena in modern medical theory? The answer is yes! Acupuncture has been widely recognized for its role in regulating internal organs, regulating nerves, regulating balance, dilating blood vessels, and relieving spasm. The decline of our body tissues is closely related to the insufficient blood supply. During the process of acupuncture, the blood vessels are dilated, the local blood supply is improved, and the decline can be delayed. It is clear that these “rejuvenation” phenomena in acupuncture treatment are not accidental, but have a theoretical basis and can be reasonably explained. In daily life, if we can pay attention to the protection and nourishment of the kidney essence, we can all achieve old age and not decline, “rejuvenation”!