Traditional Chinese medicine believes that everything is born of qi, and the four seasons are also called four seasons. Different seasons show different qi. For example, according to Neijing, spring and March are the seasons when everything comes into being, so it is necessary to "lie down at night and get up early, stride forward, and slow down to make your life"; Summer and March are beautiful seasons for all things, so we should "lie down at night and get up early, and be insatiable every day, so that we will have no anger"; In autumn, winter and March, the spirit is dull, and it is necessary to "go to bed early and get up early, have fun with chickens, and have a peaceful mind"; In winter and March, when the air is closed, it is necessary to "lie down early and get up late, wait for the sun", "cold to warm up, no skin leakage" and "keep your mind hidden." It also warns people to "nourish yang in spring and summer, and nourish yin in autumn and winter". At this point, we can see that the author of Neijing put forward the specific measures of "four qi to adjust the spirit" according to the natural change law of "spring, summer, autumn harvest and winter storage". The purpose of "four qi to adjust the spirit" is to keep the yang abundant and the human body full, so it is lively and refreshing. In ancient times, the four types of health-preserving people, the real person, the wise man and the sage, practiced the promise that "the wise man's health-preserving must be suitable for cold and summer", so they could "support heaven and earth, grasp yin and yang" and "harmonize heaven and earth" without danger. The reason why they don't do the opposite is because they are well aware of the serious consequences of the reversal of the four seasons: "If the spring qi is reversed, the shaoyang will not be born, and the liver qi will change internally; Contrary to summer, the sun is not long and the heart is hollow; Anti-autumn qi, the day is not collected, and the lungs are full of qi; Against the winter, the yin is not hidden, and the kidney is alone. " Historical experience reveals an eternal truth: "Yin and Yang are the foundation of bending time, everything is the ultimate cause, and life and death are the foundation. If they are the opposite, they will be disastrous and they will be unbearable. "