Health preservation, as the name implies, is to maintain life, and it is an activity to enhance physical fitness, prevent diseases and prolong life through health care methods and means. In other words, we must nip in the bud. If you want to keep in good health, according to the theory of traditional Chinese medicine, you should keep in good health according to the changes of the four seasons. Chinese medicine says that "Yang is nourished in spring and summer, and Yin is nourished in autumn and winter", which means that spring is the season when everything recovers, willow sprouts and the river thaws, when the weather starts to get warmer, and when the human yang begins to grow. Yang is still very weak, just like a minor child, whose function is still immature and needs someone to take care of him to avoid being hurt. The yang of the human body also needs to be maintained, so dressing to keep warm is the first priority. Although the weather began to get warmer, it was still very cold. If you take off your clothes too early at this time, your immature yang will be hurt and you will get sick easily in summer. At the same time, we should pay attention to nourishing the liver in spring, feel comfortable and have a stable mood. If the mood is unstable, it is easy to get angry and fidgety, and there will be liver diseases, such as upper gastrointestinal bleeding, which is more common. This is caused by excessive injury of the liver by anger and invasion of the stomach by liver qi. In addition, we should pay attention to light diet, so that yang can grow smoothly. We should also pay attention to more exercise. The germination of willows and the revival of everything are touching. A year's plan starts with spring. Exercise helps to develop the yang, and the yang will be sufficient and the body will be healthy in one year. Summer is the time when the sun is the most vigorous, just like people in their youth, we should pay more attention to maintaining this state and speed up the metabolism of the human body. Sweating is the expression of metabolism, and it is a period of excreting garbage and accumulating strength. Don't be too greedy. If it violates the characteristics of the season, it will be counterproductive, the sweat of the human body will not be released, and the cold and dampness will stop gathering in the body. In autumn and winter, diseases such as diarrhea and chronic cough are prone to occur. In autumn and winter, yin and cold are dominant, and yang is restrained. In autumn, crops begin to mature and harvest. As the saying goes, autumn is the harvest season. Winter is the time when everything is sealed, animals begin to sleep, and crops also begin to sleep. But dormancy and storage are periods of energy accumulation. People also need to recuperate and maintain the body's blood and body fluids. Go to bed early and get up early, don't stay up late, eat warm food, be calm and reduce all kinds of desires.