Low blood pressure?

[MrsWho]

Have just been to the gym and ended up mising out 1/2 the class 'cos I was overheating and dizzy. (was a body balcnce class and the bending down bits did it)
Instructor suggested low blood pressure (which I have had beofre when I was pregnant.
Is there anything I can do to help it?
I have an appointment at Dr for Mon.

Well if I did 8 & 10 I'd pass out

There was a lot of 10 this am and similar moves in the T'ai chi all of which I am not very good at but don't usually feel like this.