It is my understanding that these are the last times in your life you ever get to "be sick." There are no "sick days" in residency. You drag youself in, get some IV fluids if needed, and work. I was just on a rotation where the intern had a horrible sinus infection and "called in sick" and they crucified her. It seems unfair and nasty, but in this case, they had to call in another intern whose DAY OFF it was to cover the sick one! Imagine how pissed that intern was! My impression is that you have to be intubated or on the operating table to "call in sick" during residency, cruel as it is, that is how I have seen it work. If you get sick during medical school, talk to your professors and Dean of Student Affairs if it's looking bad and skip out on anything not mandatory...and enjoy the luxury of being able to do so. In my opinion, it's better to skip class and stay home and study in bed with your Robitussin and kleenex, taking naps as needed, than to expend energy dragging yourself to school where you will likely fall asleep or not pay attention anyway because you're so miserable.