MB ChB Manch 1947.
Sejrup was born in Marple on 14 October 1922. He was educated at Manchester Grammar School and the University of Manchester. After qualifying, Sejrup held junior appointments at Withington Hospital and Ancoats Hospital, Manchester. He was casualty officer at Stockport Infirmary and assistant RSO to Hope Hospital, Salford, before settling in general practice in Stockport.