People who are close to me know:
I have a friend who is Bipolar II and she tells everyone because she says she wants to warn them in advance. "I want to give them a warning letting them know what they are getting into".
For me it's a lot different. I don't tell people openly, but at the end of the day it is such a big part of who I am it's not reasonable to not tell people. If you saw someone "acting up" or being weird. Maybe even doing things that are really annoying or weird, ask yourself: If you knew that there was something wrong with them would you be more understanding? Would you want to know?
Sometimes though, it's nice to have an easy answer. At my internship I got called aside and someone said I was rolled my eyes at another worker. I didn't have to tell them about my medication or anything, I just had to say "sometimes I get overwhelmed when there is too much information to take in--I might have been acting strangely and got missread". You don't have to tell people the story or the label. Just try telling them what they need to know
I wish you luck! Just don't be ashamed.
~Lilly