Never never, never disclose to an employer until you absolutely have to. You are under NO legal obligation to reveal your diagnosis.

If you choose to do so always expected the worse, the unexpected, and the surprises. What we believe life should be in our circumstances is not how reality is in the work place.

Take it from one who learned the hard way and "trusted" my friends at work.

Well working in a small hospital where everyone knows everyone plus all their family has it's advantages but it also has it's disadvantages. Being admitted for stroke like symptoms & being dx where not only I work but also my husband works took the option to disclose or not disclose away from me. But it's my own fault for ignoring sx for years until it got to that point. :(