"Yin flavor comes out of the lower body, and yang energy comes out of the upper body. The thick taste is yin, and the thin is the yang of yin;Those who are thick are yang, and those who are thin are the yin of yang. If the taste is thick, it will be discharged, and if it is thin, it will be passed;If the breath is thin, it will vent, and if it is thick, it will be hot. The strength of the fire is weak, the spirit of less fire is strong, the strength of the fire eats, the gas eats less fire, the strength of the fire disperses, and the fire is less angry. The smell of bitterness and sweetness diverges into yang, and sour and bitter gushes into yin. If yin wins, it will be yang, and if it is positive, it will be yin. If the yang wins, it will be hot, and if the yin wins, it will be cold. Heavy cold is hot, and heavy heat is cold. Cold-wounded, heat-wounded;Qi hurts, shape wounds and swelling. Therefore, if it is painful first and then swollen, the qi injury is also formed;Those who are swollen first and then painful will also be injured. If the wind wins, it will move, if it is hot, it will be swollen, if it is dry, if it is cold, it will float, and if it is wet, it will be wet. ”
This passage is from the Yellow Emperor's Neijing, which tells about the relationship between smell and its impact on human health in the theory of the five elements of yin and yang. First of all, it explains the theory of yin and yang, that is, "yin flavor comes out of the lower body, and yang energy comes out of the upper body", which means that the negative substance is discharged through the **, and the positive breath is emitted through the upper body. Next, it elaborates on the relationship between qi and taste, pointing out that the difference in thickness determines its functional characteristics. For example, "Those who are thick are yin, and those who are thin are yin and yang;Those who are thick are yang, and thin is the yin of yang", which means that the thick taste has the nature of yin, and the thin taste is the negative yang;Thick air has a masculine nature, while weak air is masculine yin. In addition, it mentions the concept of "strong fire qi declines, less fire qi strengthens", indicating that excessive or strong fire qi consumes and weakens energy, while mild fire qi strengthens and produces energy. This theory applies not only to fire and qi, but also to the other elements of yin and yang. In addition, the text emphasizes the application of the theory of the five elements of yin and yang to the cognition of organisms, animals, plants, and food. Modern science usually focuses only on the composition and constituent elements of matter, ignoring the important constituent elements of air and taste. Traditional Chinese medicine believes that the composition of animals, plants, food, etc., is inseparable from the two elements of qi and taste, and their characteristics and functions can be understood more comprehensively through the theory of yin and yang and the five elements. The significance of studying this text is to grasp the theory of yin and yang and the five elements of traditional Chinese medicine, and to understand its way of thinking and application. By using this way of thinking, people can gain a deeper understanding of everything around them, which leads to a better understanding of the nature and inner connections of things. This not only helps people to understand the natural world, but also helps to improve their awareness of their own health and health care. 
In order to become a good TCM, in-depth study of pharmacy is essential. This is because Chinese medicine is the foundation of Chinese medicine and is in the hands of doctors"**Just as soldiers need to be familiar with guns and collect ammunition, doctors also need to have an in-depth understanding of Chinese medicine. However, learning Chinese Materia Medica is not an easy task. Due to the wide variety of Chinese medicines, the learning process is boring, and many people spend years still not getting the essentials. There are some problems with the current teaching mode and thinking. First of all, it is difficult to truly grasp the knowledge of Chinese medicine by relying only on the descriptions in the textbooks. Secondly, if you don't master the right learning methods, the learning process can become very boring. Although there are descriptions of the smell and taste of Chinese medicine in the textbooks, these descriptions are often too simplistic and do not really summarize the true meaning of animal and plant smells and tastes. In order to solve these problems, we need to use the theory of yin and yang of traditional Chinese medicine to guide learning. The qi and taste of animals and plants are classified into the system of yin and yang and the five elements, and then connected with the five organs to summarize and summarize. Only in this way can we truly understand the connotation of Chinese medicine and make learning easier and more interesting.