Very horrible thought - I also once had a friend 'X' who was close friends with the woman who worked as Receptionist in our mutual GP surgery. I'm going back decades now.
Anyhow, she (the receptionist) shared my personal medical information with my friend. Oddly though she didn't name my name, she described me in a particular way that meant my friend 'X' mistook the description for being a third party 'F'.
So next time I saw X she told me all about the medical situation of F which was in fact my own. I asked her if F had informed her all this and she said no, Receptionist, had told her but not to tell anyone. Hmmm.
So I reported this to GP who stated Receptionist would do no such thing, but she had.
What I learned from this incident is if you know someone who works in NHS or your GP or even a paramedic with access to basic info, you have no medical confidentiality.
It's one thing to say well if it was found they'd looked at your records they'd be sacked. But let's say my next door neighbour works for the hospital I'm under, is being nosey / curious, looks up my data, how the heck would I know??? I can't go to the hospital and say I believe on 'x' date my neighbour looked up my info. Ditto GP and paramedics etc.