I am 5 months pregnant and standing for over 30 minutes at a time i get kind of dizzy or lightheaded?

A "sit down" needed: Because of the increase in circulating fluid and blood during pregnancy, it is not uncommon to be "light headed" when standing from sitting or other positional changes. First, make sure that you are not dehydrated. Secondly, sit down before you "pass out". Finally, if your job requires standing,, it is time to have a "sit down" with your boss about this issue.