A word of warning about the GHIC, in theory it entitles you to the same health care as a local
In practice, in A+E in Italy, public hospital they refused to acknowledge it. I needed anti biotics, terrible kidney infection, were going to charge me 300 euro, told me I had to pay due to Brexit (this was 2 years ago), I kept trying to explain about the GHIC card, loads of nurses all talking to each other around me in fast Italian, shaking their heads, tut tutting, insisting I have to pay. I had been there about 4 hours by that stage. I dont speak the language.
I had to leave and find a private practitioner who charged me 100 euro for the consultation and anti biotics. I couldnt claim on my insurance as it was less than the excess (as would have been the hospital charge).
And again on this thread as with most threads about holiday insurance, people really dont understand the difference between pre existing conditions and 'under investigation'
If you have any referrals on the boil (and I have 3, waiting nearly a year for the consultant appointment which still wont give a definitive diagnosis) you are on very thin ground with your current insuraer (and you must let them know) but you will find it very very hard to get brand new insurance because the minute you say 'yes' to the question, they wont insure you.
Ive been asked by Staysure who Im with, that I need a certificate for 'fitness to fly' following referrals (even though they're basic things like a referral for rheumatology, ENT type things, and another one) and the GP wont do this, they dont comment on fitness to fly
Therefore anything that staysure deem might be connected to my undiagnosed conditions (if in fact they are 'conditions') I wont be covered for. That gives them massive wriggle room
Additionally, I find they dont like it when there is no conclusion to a referral or GP visit, the visit might have been to explore x, y, z and nothing comes of it, no referral, no medication no diagnosis, they dont like that uncertainty.
I have a myriad of low level health stuff, the usual, migraines, HRT symptoms, some back issues, possibly Raynauds, possible eustachian tube dysfunction, all of which are waiting on consultant appointments which literally are taking years and years and this puts my premium up because they are not formal diagnoses yet. (or many never be)