Tell who you want and need to tell. I trust my manager/supervisor and told him and that person is to keep your privacy. Only because there were days I went to appointments that I may have needed to stay longer or could leave sooner and come back to work. Whatever I could do to save my PTO. I took a week off for surgery and I wanted him aware if anything was wrong when I came back, just in case. As far as my other co-workers, I slowly came out and started to tell only certain people because I felt comfortable enough to do it.
Assess your situation and make sure YOU are comfortable.
