A physicans assistant at the doctor's office where I am being treated after an accident told his mother about my case and she in turn told my supervisor (she is a co-worker). He told more than So and so got hurt. He told details and even told her when my follow up appointment was.

Yes. Why are you so concerned if this was an accident you where in? Didn't you contact your supervisor and tell them about the accident (if you had to miss work)? What part do you object to that was disclosed? The part where you had an accident or the part where you have a follow up appointment?

Was a specific aspect of your accident supposed to be confidential such as what pain meds you were prescribed, for instance?

The part where he told his mother and what she was telling my supervisor and the instructions that my doctor gave me were not the same and it caused trouble for me at work

How old are you ? Are you a minor ?

So you report them to the medical facility. So the instructions from the doctor would be in writing,

What trouble did it cause ?