Are there side effects of Polycythemia Vera

Just wondering what side effects are there to this b… condition??? I already have underactive thyroid and now find that it is looking very likley that I have Arthritis which is very sore, My Doc says it is related all though I have never heard of this before.
Any one else have or heard of this
Thanks for your time

One side effect that I have is that my vision gets a little blurry when numbers get elevated.