I used to hide my problems everybody. It was a shame for me to show up people that I was so different. I neither wanted my parents were worried for me.
Now, I accept myself and if I have to tell someone something about my condition I don't feel as if I were loosing something of me anymore.
Nontheless, I only talk about it when there is a good reason behind it and like, CK2d says, depending on the person.

Of course, I never say I have AvPD. It would tell me a long time explain what it is and in the most of cases, it would be in vain. I say I have social phobia, anxiety or depression.