Two elbows, two axils, two moustaches, two nests. Huangdi Neijing said: "People have eight deficiency, lung and heart evil, and qi is at two elbows;" The liver is evil, and its airflow is in the armpit; Spleen is evil, and its qi stays in the second beard; Kidney is evil, and its qi stays in two phlegm. "Exogenous pathogens stay in the body for a long time, which hinders the operation of meridians and easily stays in elbows, axils, beards and poplites on both sides of the human body, that is, the five internal organs hide pathogens in this" eight deficiency ".

1, Huangdi Neijing is divided into two parts: Lingshu and Suwen. It is the earliest medical classic in China, and it is also one of the four classic works of traditional medicine (the other three are Difficult Classic, Treatise on Febrile Diseases and Shennong Herbal Classic).

2. Huangdi Neijing is a comprehensive medical work, which established the theories of Yin and Yang, five elements, pulse condition, Tibetan image, meridians, etiology and pathogenesis, diagnosis, treatment, health preservation and luck.