In the short story collection The Thirteen Problems, Dr Lloyd is a physician in St. Mary Mead and member of the Tuesday Night Club.
Lloyd seems to have led a surprisingly active and adventurous life previous to settling down in St. Mary Mead going by his contributions to the Tuesday Night Club. Of course once he's taken up practice in St. Mary Mead he no longer has to travel to find excitement, as local GP he is invariably an active participant in detecting the numerous murders that enliven village life.
He spent several years working as a physician in Las Palmas on Gran Canaria, and some time later in Australia.