Sasang Medicine, the only complete Korean medical system and philosophy, is made accessible in English for the first time through this annotated translation of Lee Je-ma's foundational text, the "Dongeui Susei Bowon." Including a philosophical exploration of human emotions and constitutions, and comprehensive explanation of the Four Constitutions and their effects on health, the "Dongeui Susei Bowon" offers a unique approach to any health concern. It also includes examples of specific cases and how to apply over one hundred herbal formulae for effective treatment according to the energetic requirements of each Sasang constitution. Rigorous translation, explanatory introduction explaining the relationship to and differences from Chinese medicine, detailed footnotes, and commentary by a practicing doctor of Korean medicine fully elucidates Lee Je-ma's text for a thorough understanding of Sasang Medicine.