This can have many causes, hypotension, hypoglycemia, dehydration. more concerning is, if one has heart issues then lack of blood flow to the head. Try get up slowly instead. It happens to me on occasion but mostly when it's hot and don't drink enough water, I also have hypoglycemia. For me it doesn't have any link to my seizures. I only feel dizzy from seizures and have trouble walking a few hours after I've had one, but then it passes.