My daughter is 17 years old. She has spells where she feels lightheaded and everything goes white for a few seconds. She has them multiple times a day. She gets them when going from sitting to standing but also when she's just walking. She gets them at all times of the day and both before and after meals. It has already been determined that she has normal blood sugar. The neurologist diagnosed it as vertigo a couple of years ago. But she doesn't see spinning or feel like she's spinning. The real twist here is that she lived in Spain for the past school year and she didn't have this problem even once. It makes me think allergies. But she has no other allergy symptoms. I was thinking of trying Flonase to see if that works. Any other thoughts or ideas would be appreciated.