According to my dr’s, caffeine can and does affect your bloodwork

Could that have been from the stress of being in the hospital? Sometimes if we get upset or stressed it can cause blood pressure and sugar levels to go higher. ( just curious) They are natural reactions.

I've never had issues with it affecting blood test of other lab results.
I'll have morning coffee & when stressed or at a restaurant I'll easily put 6 cups/day with no issues other than BP

As an aside, I found out through a DNA research project that I have a gene that allows me to metabolize caffeine faster than most. So maybe coffee before blood work is not that big a deal for me.

I don't think. Im not a coffee drinker. I do drink tea and hot chocolate. They don't seem to have any effect.