What are the types of identification in Chinese medicine?

In Chinese medicine, there is "identification" of yin and yang, deficiency and reality, surface and interior, cold and heat, and qi, blood and fluids. The so-called disease is the battle of the defenses possessed by the organism against various pathogenic factors, i.e., hostile forces of the organism, which attack the organism from inside or outside. The internal ones include cancer, lesions and autoimmune diseases; the external ones include pathogenic microorganisms such as bacteria, viruses and malaria parasites, as well as light, dust and smoke. The so-called defense forces are the reticuloendothelial system of the body, i.e., the system that maintains the health of the body through humoral immunity and cellular immunity, among others. Disease is a state in which these two forces are engaged in battle with the body as the battlefield, and on both sides of the battle, there will be winners and losers.

In the early stages of the battle, the strength of the defense forces is almost 100%, as the battle proceeds, the power ratio of the two sides will change significantly. By the time of death, the hostile side's strength reaches almost 100%, while the defense strength will drop to zero.

But in the middle of the battle, there is a period of time when the forces of the hostile side are evenly matched. For a machine, before this time is a period of being at an advantage, and afterward is a period of being at a disadvantage.

In Chinese medicine, the period of superiority is called "yang" and the period of inferiority is called "yin". This means that yin and yang are both "standards" for disease progression and "standards" for physical exertion and growth.