I know health! Health preservation refers to a medical activity to support life, enhance physical fitness and prevent diseases through various methods, so as to achieve longevity. In the modern sense, "health preservation" refers to the active physical and mental maintenance activities for material and spirit according to the laws of human life process. The so-called life is life, survival and growth; The so-called maintenance means maintenance, recuperation and nourishing. In a word, keeping in good health is to maintain life. Guided by the theory of traditional Chinese medicine, we should follow the changing law of the biochemical set of Yin-Yang and Five Elements to scientifically recuperate human health and vitality. Psychological health preservation refers to the method of nourishing the heart, regulating the mood and life, so as to achieve the purpose of maintaining the body, reducing diseases, improving health and prolonging life.