In 1880, Doyle returned to medical school. Back at the University of Edinburgh, Doyle became increasingly invested in Spiritualism or "Psychic religion," a belief system that he would later attempt to spread through a series of his written works. By the time he received his Bachelor of Medicine degree in 1881, Doyle had denounced his Roman Catholic faith.
Doyle's first paying job as a doctor took the form of a medical officer's position aboard the steamship Mayumba, travelling from Liverpool to Africa. After his stint on the Mayumba, Doyle settled in Plymouth, England for a time. When his funds were nearly tapped out, he relocated to Portsmouth and opened his first practice. He spent the next few years struggling to balance his burgeoning medical career with his efforts to gain recognition as an author. Doyle would later give up medicine altogether, in order to devote all of his attention to his writing and his faith.