Witts graduated in medicine from the University of Manchester in 1923 and took the MD in 1926. He was Nuffield Professor of Clinical Medicine at Oxford University. A physician, Witts was well-known for his studies of anaemia. At Oxford, he built up haematology as a significant clinical speciality. Witts was the author of Anaemia and the Alimentary Tract(1956) and The Stomach and Anaemia(1966). Witts died on 19 November 1982.