Traditional Chinese medicine (TCM), Japanese-Chinese medicine, and Korean Sasang constitutional medicine have common origins. However, the constitutional medicines of China, Japan, and Korea differ because of the influence of geographical culture, social environment, national practices, and other factors. This paper aimed to compare the constitutional medicines of China, Japan, and Korea in terms of theoretical origin, constitutional classification, constitution and pathogenesis, clinical applications and basic studies that were conducted. The constitutional theories of the three countries are all derived from the Canon of Internal Medicine or Treatise on Febrile and Miscellaneous Diseases of Ancient China. However, the three countries have different constitutional classifications and criteria. Medical sciences in the three countries focus on the clinical applications of constitutional theory. They all agree that different pathogenic laws that guide the treatment of diseases govern different constitutions; thus, patients with different constitutions are treated differently. The three countries also differ in terms of drug formulations and medication. Japanese medicine is prescribed only based on constitution. Korean medicine is based on treatment, in which drugs cannot be mixed. TCM synthesize the treatment model of constitution differentiation, disease differentiation and syndrome differentiation with the treatment thought of treating disease according to three categories of etiologic factors, which reflect the constitution as the characteristic of individual precision treatment. In conclusion, constitutional medicines of China, Japan, and Korea have the same theoretical origin, but differ in constitutional classification, clinical application of constitutional theory on the treatment of diseases, drug formulations and medication.
Keywords: Comparative Study; Constitution; Constitutional Theory of Traditional Chinese Medicine; Japanese–Chinese Medicine; Korean Sasang Constitutional Medicine; Review.