My BP was normal pre-weight loss (at about 120/80) but now it is very low (100/70 or 90/60) and I get dizzy quickly. I also black out. It hasn't happend very often, only 3 times, but that is enough to freak me out (once it was in the underground in london and I lost my hearing before I lost my sight and started to collapse, it was the single most awful experience ever, the ones after this have been less traumatic). But the good thing is, all my black outs have been when I hadn't eaten in a long while (20 hours plus) and when I was standing for prolonged times, so if I eat regularly it should not happen!
The way I see it, low BP is better than high BP, only very very very few people need treatment for low BP, while high BP is very dangerous. So let's just count our blessings and just be happy that we are lucky and have low BPs!
Camy