Due to the frequency and duration of my handwashing, my hands are very dry and discoloured, so I get a lot of questions about them. I don’t make a habit of bringing my OCD into conversation, but I’m often called upon to explain it anyway. I keep it short and people don’t linger on the topic, so it’s not a big problem.
While I was still in school, though, I don't think there was anyone who didn't know. My friends knew because it was necessary. I didn't get any pity for it and I don't feel like I was outcasted (other than the occasional person that would just call me stupid), but for a lot of people it was a source of entertainment. I was fine with people laughing with me about it, because I need to be funny in social situations or I'll just feel really uncomfortable. So most of my friends probably don't understand how difficult it really makes things for me, but that’s my fault, since I didn’t really tell them. Usually I keep it to myself because they don’t need my problems on top of their own.
My comparatively mild social anxiety and other issues, though, I don't mention very much. Those I can hide sometimes.