I think it depends on what your limitations are. I feel it is no one's business if I have MS. I help with the things I can and if I can't, I find another way to contribute. So I don't stand in the hot sun all day with the bake sale; I bake a few extra things and just say I am not available.
My daughter doesn't want me to tell people, she says they might think I am "using" MS. First and foremost, I do what makes her comfortable. Her close friends know and are great to offer her a ride when I am not up to driving; I give them gas money 'cause it is such a help to me.
I have MS; it doesn't have me.
Good luck!