From 1900 to 1905 he served as a surgical assistant in the university clinics at Berlin and Marburg, and afterwards opened a private surgical practice in Rostock.
As a hospital physician during World War I, he lost an arm as the result of a septic infection, thus ending his career as a surgeon.In 1919 he obtained his habilitation with a thesis on the medieval surgeon Guy de Chauliac, and in 1924 became an associate professor at the University of Rostock.
From 1934 to 1950 he was a professor of the history of medicine at the University of Leipzig.From 1934 to 1950 he was director of the Karl Sudhoff-Institut fĂĽr Geschichte der Medizin und der Naturwissenschaften (Karl Sudhoff Institute for the History of Medicine and Natural Sciences) at Leipzig.
From 1947 to 1951 he was vice-president of the Deutsche Akademie der Naturforscher Leopoldina.