Blood pressure and pulse

I have borderline low blood pressure at 110/50 which leads to head rushes when I stand up. I used to pass out a lot when I was a child because of it. After having general anesthetic it gets even lower to 80/40 and they usually give me some horrific glucose syrup to drink to perk me up enough to turf me out of their bed.

Maybe I need to eat some fat and get stressed.

Doesn't work, I eat loads of fat and am super stressed but still have very low blood pressure and the accompanying dizziness and blackouts.