Light headed and dizzy. What causes that? Its happened two days in a row now

Dehydrated. Feeling light headed & dizzy are common signs of dehydration or not getting enough calories. Drink plenty of water each day & make sure you are not skipping meals. Try eating something small, like a few crackers. However, this could be something more serious (ex. Infection, not enough info to tell) so if it gets worse or doesn't go away please see a dr.