When was the Huangdi Neijing written?

Spring and Autumn Period, Warring States Period and Western Han Dynasty. The compilation of Huangdi Neijing is an important milestone in the medical history of China. Huangdi Neijing, referred to as Huangdi Neijing for short, is the foundation work of China's medical theory and the most original medical thought. Huangdi Neijing, composed of Su Wen and Ling Shu, was compiled by Bing Wang in the Tang Dynasty and Songshi in the Southern Song Dynasty, and has been handed down to this day. There are 162 articles today. Its completion is a long historical process, and the evolution process is complicated after many times of arrangement. As the originator of TCM constitution science, Huangdi Neijing put forward a variety of constitution classification methods. According to the viewpoint in the book, the formation of human physique is summarized as being influenced by congenital and acquired factors. Huangdi Neijing discusses the formation, changes, characteristics, constitution and health preservation of the human body, and has made great contributions to the development of TCM constitution theory.