I used to get doctor's notes with very extensive and intimate diagnoses - I'd give them back to my employees and tell them to have the doctor give me a note that said "I treated Mrs./ Jones on the afternoon of Thursday July 12." Especially with current privacy laws, I don't want the intimate details of my staff's reproductive health (or whatever) floating about on paper records accessible by dozens of people.
An employer certainly has no need or right to know the medical details of the treatment that kept you from work, unless those details are going to prevent you from doing your job, or are going to change the way you get it done - that is, you've acquired a disability that requires accomodation from your employer in order to continue performing your job.
Of course, if you've got a communicable disease, that's appropriate to put on a doctor's note - "I treated Mrs. Jones for influenza." However, if there's no diagnosis on the note, your employer can safely conclude that whatever it is you're being treated for, he can't catch it.
If, for example, you're pregnant, your employer doesn't need to know until the pregnancy impacts your work. If you have a good relationship with your employer, you'll give him plenty of advance warning, but if you work for a reactionary troglodyte, the sort of person who'll look for reasons to fire you as soon as it becomes evident that you're more than just an indentured servant, you'll wait until the last reasonable moment before alerting him, because he's going to find a reason to discharge you regardless.
This answer was edited by GADale 96 days ago.
Reason: typos and clarification
