Huangdi Neijing is divided into Lingshu, which was jointly created by the famous work Huangdi's Name and Su Wen by Tuo Xuanyuan, an ancient physician, and medical theorists. It is generally believed that it was written in the Spring and Autumn Period and the Warring States Period.

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

Huangdi Neijing is a comprehensive medical work, which establishes the theories of Yin and Yang, five elements, pulse condition, Tibetan image, meridians, etiology, pathogenesis, symptoms, diagnosis, treatment, health preservation and luck. Its basic material comes from the long-term observation of life phenomena in ancient China, a lot of clinical practice and simple anatomical knowledge.

References:

Baidu encyclopedia entry? Huangdi Neijing