The Germination Stage - During the Shang Dynasty, the "physician for internal diseases" can be regarded as the earliest internal medicine doctor.

The Foundation-laying Stage - From the Spring and Autumn Period and the Warring States Period to the Qin and Han Dynasties, Huangdi Neijing is a great medical work. It records the causes and pathogenesis, symptoms, diagnosis, and treatment principles of internal medicine diseases, reflecting the holistic concept and the theory of syndrome differentiation and treatment. Shanghan Zabing Lun established the theoretical system of syndrome differentiation and treatment based on the six channels as well as the theoretical system of syndrome differentiation and treatment based on the zang-fu organs and meridians, which includes theories, methods, formulas, and herbs.

The Enrichment Stage - From the Wei and Jin Dynasties to the Jin and Yuan Dynasties, the etiology, symptomatology, and therapeutics were enriched and developed, as seen in works such as Zhouhou Fang (Emergency Prescriptions Kept Up One's Sleeve), Zhu Bing Yuanhou Lun (Treatise on the Causes and Symptoms of Various Diseases), Qianjin Yaofang (Essential Prescriptions for Emergencies), and Waitai Miyao (Arcane Essentials from the Imperial Library). There were also innovations in academic theories, such as the doctrines of the Four Great Masters of the Jin and Yuan Dynasties. Liu Wansu advocated the theory of heat and fire and mainly used cold and cool herbs; Zhang Congzheng focused on expelling pathogenic factors in treating diseases; Li Dongyuan first proposed the theory of internal injury of the spleen and stomach; Zhu Danxi created the theory of "yang is often excessive and yin is often insufficient". At this point, the system of internal medicine in traditional Chinese medicine was initially formed.

The Formation Stage - During the Ming and Qing Dynasties, Neike Zhaiyao (Abstracts of Internal Medicine) was the first work named after "internal medicine". Ye Tianshi and Wu Jutong respectively established the theoretical system of syndrome differentiation and treatment based on the defense, qi, nutrient, and blood aspects and the theoretical system of syndrome differentiation and treatment based on the triple energizer, enriching the system of febrile diseases in internal medicine.

A Brand-new Period in the Development of Internal Medicine in Traditional Chinese Medicine - Since the founding of the People's Republic of China, the state has attached great importance to the collation and research of traditional Chinese medicine theories. A large number of medical monographs have been published and issued, and the textbooks of internal medicine in traditional Chinese medicine have been continuously updated. So far, the seventh edition of the planned textbooks has been further issued. The development of the entire discipline has been gradually formed and improved along with the historical process and the development of medical practice.

In the long history from ancient times to the May 4th Movement, the Chinese people continuously practiced and explored in the struggle against diseases, rising from experience to theory and constantly developing and improving. They created the splendid traditional Chinese medicine and also established and developed internal medicine in traditional Chinese medicine. The development history of internal medicine in traditional Chinese medicine has roughly gone through the germination stage, the foundation-laying stage, the enrichment stage, and the formation stage.