Good thing you decided not to go to medical school. You definitely couldn't hack a hard schedule.
The point is that Doctors generally live less than the "average" person in the U.S. due to the lifestyle. (Night Cargo pilots as well.)
I have been doing red eye's the last 5 months and I can definately say that it takes my days off to fully recover. I bid them to commute and cannot do it anymore. No job is more important than your health.