Lei Yixian, also known as Huanran, with the courtesy name Chuntai, lived during the Jiaqing and Tongzhi periods (approximately until 1861). Originally from Fujian, he later moved to Quzhou (present-day Quzhou City). Due to financial difficulties, he abandoned Confucian studies to pursue medicine, studying under Cheng Zhitian from Xin'an, from whom he fully inherited the medical tradition. During the Daoguang period, his entire family moved to Longyou, where he practiced medicine in the city. Known for his noble medical ethics, he treated all patients with equal dedication and care, regardless of the severity of their illness or their financial status. He authored "Medical Encyclopedia" in forty volumes and "Medical Essentials" in four volumes (unfortunately, these works were never published).