On Mon, 12 Apr 2021 06:58:52 -0700 (PDT), polygonum_on_google
wrote:
snip

I have read doctor's letters (specifically one copied to my partner about her then recent appointment) in which the consultant completely confused hyper- and hypo-.

Indeed, I often see that mistake being made by many doctors - GPs, registrars, and consultants - where the meaning really, really matters. Sometimes it is the patient mis-copying but sometimes a scan of the letter demonstrates that it was a mistake by the qualified medical person.

But how often would such a mistake remain confused when seen in
context?

Possibly sometimes it is the medical secretary but the doctor is the person who signed it and is responsible.

I think I'd be more worried if they didn't know their left from right
(and another thing that does seem quite common)?

Cheers, T i m