Privacy schizos need to stop making up nonsense. All of your diagnosed illnesses are permanently stored in a database that will never ever be deleted until decades after your death. This data is already shared between all hospitals. The moment you step through the hospital door you aren't at home and your privacy fantasies end. Literally any malicious worker could leak your data and then what? Why does this even matter. If I see you in a street, I can tell you're sickly just from the direction you're walking in.
Yes, that's a very abstract statement that seems plausible and is easy to make, but how do we know there's significant harm? What are some real-world examples? Can we quantify how much harm is done to patients from sharing too much, versus sharing too little?
Sharing patient data harms privacy, but in the long run more data sharing is probably the best route for reducing physical harm. The body is just too complicated for individuals to fully grok.