In the UK our National Health Service (NHS) have an app for that (not blockchain):

I don't have it installed because I never need the doctor.

It would be good to be able to self sovereign that data, but at the same time, authorised health care workers would need access to that in an emergency if you weren't able to give them direct access.


https://i.nostr.build/1ZW7u78NC4BKVvlZ.jpg