A lot of us might not be here if it weren't for the medical professionals who study blood and guts and bacteria. That doesn't mean most of us have any desire to study those things ourselves—but we might like to read about the kind of people who do. The crazy thing about many of the doctors and nurses who end up with biographies chronicling their lives and adventures is how selfless they often were.
Medical work can be unsettling, gross, scary, and sad. It's rarely pleasant. For every success story there are a dozen failures, a dozen instances in which medicine and surgery couldn't save a life. Even today, with medical technology more advanced than doctors two or three generations ago could have imagined, failures prevail.
Men and women willing to endure such constant defeat in less-than-desirable conditions are worth reading about. Many of them have been Christian missionaries, and don't give up because their work is far more than saving bodies. Whatever inspires medical professionals to pursue the kind of careers they do is worth finding out, and these books will help you do just that.