s) , When your BP is low, you tend to get dizzy upon standing, although I would get dizzy and flushed when standing to fast with
high blood pressure, but you are saying you feel
pressure in your face, that could be a sinus problem (Fluid) or maybe a sinus infection or allergies, (Just a Guess) The only way to be sure is to have a blood work-up done to find out about a thyroid problem, some of your symtoms do come on with thyroid, I would see an md and get a check up.