If you found out that you had a disease that wouldn't necessarily kill you, like diabetes, would you tell anyone?

Diabetes II and I kill most of the time.  Not sure why anyone but the doctor needs to know...

You need to make sure that people who are close to you know what is going on and how to help you if you have a problem .

Please don't be ashamed. It's a disease.

Well I have diabetes, and those in my life that need to know, know. I don't meet someone for the first time, tell them my name, and stick a medical history in their face after the handshake.

If the topic comes up, people find out, otherwise it may be years before a random acquaintance, may find out anything about me other than my name and that my favorite drink is home brewed ginger beer. 

That would REALLY depend on their need to know.  I can't think of any disease/condition that I would be too embarrassed to tell anyone else about, but then I'm really open-minded.

It would depend on their need to know.

Close family, members of your household, friends you share meals with, someone in charge of catering a function you are attending, your employer, all have a reasonable need to know.

If it were diabetes, I'd have to because there are massive dietary changes and possibly daily injections that go along with having it, which seeing as how I live with my wife and three kids would make it impossible to not tell anyone about it. Seriously, my wife'd be all, "Oh, honey, why won't you eat sugar any more and what's with all hypodermic needles and you always injecting yourself?" So, what would I say, "Oh, that's nothin', babe. I've just taken up Atkins and heroin"?