I don't call myself mentally ill. No one I know with conditions like diabetes or whatnot calls themself ill. They have a condition, but don't seem to call themselves ill. I don't consider myself to be ill. I'm disordered, yes... but not ill. I don't have a disease, or an infection... I have a disorder whereupon my brain doesn't work quite the way it should.

If I have to, I'll use "mental health issues", or I might say "I have a mental health disorder". Usually I just say "I have bipolar 2," because other people would say "I have diabetes/Crohn's/etc". I'll just call it what it is.

Then again, I'm also more apt to describe myself as saying that my brain is wired differently than it should be. Some of the wires just don't go where they should be!