When I have to explain I say I have a neurological disorder and give the name of it. I keep it short and tell them it causes pain and effects my mobility. To be honest though other than because of the lack of awareness, I don't see why someone 'different' should feel they have to explain. People are nosy and think it ok to ask what's 'wrong' with people like us, but they wouldn't dream of intruding on other people's personal business. I don't personally like the great big long "Understand me" type posts that you see for many chronic illnesses. To me they seem almost combative and selfpitying. That's not to say others shouldn't use them, I just personally switch off to that kind of thing and if I do I can't expect others not to. I keep it short, simple, polite and not woe is me as I don't like a fuss or for other's to think I'm after pity. I'd like more people to know about CRPS but at the same time I'd like to think that by keeping it fairly open/positive they might go off and look it up.