After house jobs in Eastbourne and Portsmouth, Aldridge was commissioned into the
Royal Army Medical Corps. From 1956 to 1959 he was a medical specialist in the
British Military Hospital, Tripoli. Returning to civilian life, he joined the Reed Paper Group as Industrial Medical Officer. From 1963 to 1987, he was Chief Medical Officer of IBM UK Ltd. He was Civil Consultant in Occupational Medicine to the
Royal Navy, 1983–1992. As well as serving as Dean of the
Faculty of Occupational Medicine, Aldridge was an active member of the
Royal Society of Medicine, the
British Medical Association, the
British Occupational Hygiene Society, the
Royal Society of Tropical Medicine and Hygiene, the Society of Occupational Medicine, and the Internal Association of Physicians for Overseas Services. ==Honours==