Born in British Guiana the son of Arthur Henry Thomson, a colonial civil servant, he was educated at Dulwich College and Birmingham University, where he graduated in 1915 with first class honours in medicine, surgery and midwifery.
He was also awarded the gold medal in clinical medicine, the Russell Memorial Prize, and was both Queen's and Ingleby Scholar.
[1] After graduation, he joined the Royal Army Medical Corps as a Captain and served as a Regimental Medical Officer with the Guards Division in France during World War I, where he was awarded the Military Cross and the Croix de Guerre, and was Mentioned in Despatches twice by the British and once by the French.
[1][2][3] After the war he was appointed Assistant Physician at Birmingham General Hospital, where he was elected MRCP in 1920 and obtained his MD in 1923.
Later in life he focussed his research activity on to ageing and chronic sickness, giving the Lumleian Lectures on the subject in 1949.