Zhu Dan-xi was the last of the four great masters of internal medicine during the Jin/Yuan dynasties. He is remembered today as the founder of the School of Enriching Yin. However, Zhu studied the theories and methods of the other three great schools before him and especially that of Li Dong-yuan. This book is a record of Zhu's differential diagnosis, treatment, and case histories of a wide variety of internal and external diseases. This book is the source for many standard pattern discriminations and treatments found in modern internal medicine texts.