If someone told me he or she had a disability of any kind, I would respond with sympathetic concern and probably ask some questions about it, assuming that that would be okay since they brought it up. I would probably feel that they were expressing their trust in me to tell me about it.
Unless it’s a member of my immediate family, husband or child or parent or sibling, I don’t think they have any obligation to tell me. That’s up to them. I would want to be able to make special allowances as needed, taking my cue from them, but I would not feel that they owed it to me.
I never told any member of my husband’s family about mine because I knew exactly how they would react. It would be a big huge calling-attention fuss at every possible occasion, as if they were just going to worlds of trouble to be considerate and accommodating, no matter how many times I told them that everything was fine and nothing special was needed and I would take care of it. I know this because I did tell them about one thing years ago, and found it was mentioned as often as possible with respect to just about everything we ever did together. Later when the second and more serious condition arose, I swore they were never to know.
As for friends and coworkers, that would depend on their level of comfort and our degree of closeness. I will keep anyone’s secret about anything,* but some people dread being talked about or questioned or treated differently, and so they say nothing. Again, that’s up to them, and I would utterly respect their decision.
—-
*Except where someone is being harmed.