Confidential Medical Information shared

[Sproglets]

I have a long term health condition, the team I work in knows what the condition is as I shared the information with them myself. My boss knows about things in greater detail, again, because I told him. He has told other members of the team the things that he knows and they didn’t. Would I be correct in thinking that this is a massive breach of confidentiality and what is the best thing to do now going forwards?
Obviously I can’t undo what has been done, but I also don’t want to do nothing. To be honest, I’m pretty angry about the whole situation and don’t want him to get away with it as it were.
Anybody got any advice?

Why did he share the information?

At what level in the organisation is your boss, and what would you like to happen?

I don’t know why he told the others, and I can’t work out what benefit the knowledge is to them. It does make me very uncomfortable knowing that they know.
I guess I’d like an apology, him to accept that he was wrong. I’d like to know how widely he shared the information and an assurance that it isn’t going to happen again.

Can you speak to him about it? Yes it's a beach of confidentiality. If he doesn't apologise profusely then can you raise a grievance?

Did he know they didn't know as many details?

Yeah he did know the others couldn’t have known about what he then went on to tell them.
It relates to things that happened before they worked in the team.

I will try to raise the issue with him but, from past experience, I know he’s not particularly receptive to being challenged about things he’s got wrong.