After spending one year as the house surgeon in the
Royal Infirmary of Edinburgh, Hood joined the
Royal Army Medical Corps (RAMC). He served in France and Belgium during the
First World War, and then in India and Afghanistan shortly afterwards. He became a specialist in
pathology, serving in
Meerut and
Bangalore and then as deputy assistant district pathologist for
Madras region. Hood conducted research on
cerebrospinal meningitis and
pneumonic plague, and in 1929 he was appointed assistant district pathologist to
Southern Command. As DGAMS, Hood was credited with supporting developments in Army Psychiatry, helping to provide forward surgery and reorganise field medical units, and organising a blood transfusion service. By August, he was also honorary physician to
George VI. He served for far longer as DGAMS than was usual. He also decreed that medical research conducted on soldiers should be solely for the purpose of preventing and curing disease and allaying injury. Hood had hoped to become the first head of combined medical service for Navy, Army and Air Force, but this did not happen. ==Civil career==