I think my characters are all more or less matter-of-fact about not feeling well.

Cal spent a good chunk of his life addicted to various drugs; the biggest surprise of finding himself resurrected in a fully repaired body was that he suddenly didn't feel like crap. Even though he'd been clean for while beforehand, he'd still done a lot of damage. So, if he were to get sick now, I think he'd have to be pretty sick for it to really get to him.

Steven works in a restaurant and is long since used to powering through any illness that leaves him with the ability to remain upright, and a few that don't. Of course, he is also happy to milk any and all illnesses, real or imaginary, for sympathy, particularly in the company of attractive women.

Javert does not get sick. I mean, he probably does, but you'd never know it from looking at him.