Not sure what anecdotal evidence you're leaning on to prop up that argument. My mother used to work herself to the bone even with a cold.
I suffer quite continual pain in my back, and have a bad habit of working through an illness to the point of exhaustion. I know plenty of friends who do the same, rarely complaining.
A girl and her brother that I know are constantly ill - and moaning about the smallest thing.
So it is a personality issue, I suspect, nothing to do with gender.