MB ChB Manch 1942; LRCP MRCS 1943; MRCP Eng.
Greenwood was born in Glossop on 28 December 1917. He was house surgeon at Stockport Infirmary before serving as a medical officer in India, Chindwara and Dalhousie during the War. He was later house surgeon at MRI then held registrar positions at Park Hospital, Davyhylme, MRI and Withington Hospital Manchester. Greenwood was a member of Manchester Medical Society . He later left Manchester and was senior registrar at King's College Hospital and Royal Sussex County Hospital, Brighton, before being appointed consultant (physical medicine) for Bromley Area Health Authority.