He was educated at the Royal Grammar School, Newcastle upon Tyne, Jesus College, Oxford (Exhibitioner; Honorary Fellow, 1966), and Westminster Hospital (Scholar).

Following the start of World War II, he joined RAFVR Medical Branch, October 1939.

He was attached to the Greek Air Force, 1941; Squadron Leader, 1942; Senior Medical Officer RAF Naval Co-operation Group in Mediterranean, 1942.

He advised Aneurin Bevan on the attitudes of medical practitioners to the creation of the National Health Service in 1948.

[1] On 18 December 1964, he was created a life peer as Baron Segal, of Wytham in the Royal County of Berks.