can be due to poor hydration - ie you haven't drunk enough. If it has been hot it may be that your blood vessels are more dilated than usual.
OR there may be a more suspicious cause, like a heart problem - but you'd probably know about that by now if it were serious. I have slightly low blood pressure and frequently have "dizzy spells" when I get up. My heart also sometimes does this weird thing where it kinda feels like it stops for a bit then races to catch up with itself... did that make sense? I've had both checked out and it's fine.
If you are worried or have a history in your family of low blood pressure, you can always get your GP to check it. http://www.betterhealth.vic.gov.au/BHCV ... enDocument
35kg lost. (November 2005 - October 2006)
15kg gained again (as at October 2010).
Back to the drawing board - Let's do this thing!
"You can't change the winds, but you can change the sails"
"Reach out and take control of what lands in your lap"