Zhu Zhenheng (Chinese: 朱震亨; pinyin: Zhū Zhènhēng; 1282–1358),[1] courtesy name Danxi (Chinese: 丹溪; pinyin: Dānxī),[2] was a Chinese physician and writer active during the Yuan dynasty. Initially trained in classics as a fourth-generation follower of Confucian philosopher Zhu Xi, he decided to pursue a career in medicine after failing his civil examinations twice. After his death, Zhu's teachings continued to be compiled and circulated by his followers well into the Ming dynasty. In modern histories of medicine in imperial China, Zhu is referred to as one of the "four great masters of the Jin-Yuan scholarly medical tradition".