If you ever had a cardiac catheterization procedure (a tube fed through a large vein into your heart), you know that it is not something you would want to go through alone. You’d want to have a team of trained professionals there to prep you and sterilize things, and an X-ray machine to help the doctor guide the tube into the heart.
But somebody had to be the first person to be catheterized, and it turned out that patient, Werner Forssmann, was also the first doctor to perform the procedure; lacking approval to try it on anyone else, he performed it on himself in 1929.
His boss at the August Victoria Home at Eberswalde near Berlin was displeased with his dangerous self experimentation. Forssmann ended up leaving cardiology and becoming a urologist. He married a fellow urologist with whom he shared a practice after World War II; they had 6 children. He was a Nazi Sanitary Officer, but was captured and spent time as a prisoner of war.
Though his colleagues at first considered him crazy, by the 1950s his work was recognized as important. In 1956 Forssmann shared the Nobel Prize for Physiology or Medicine with Andre Cournand and Dickinson W. Richards “for their discoveries concerning heart catheterization and pathological changes in the circulatory system.”