My 13 year-old daughter has recently begun having dizzy and near fainting spells. The only change in her life over the past month has been the addition of summer workouts for softball. They are pretty intense, and although she is a very active athlete, she is some what over weight. We went to a Gp about the sells. She said possible dehydration and not enough protein. We are changing her diet to accommodate. The spells do not occur at any particular time...and they se to be worse about an hour after eating. We have noticed that her blood pressure goes from 119/74 to 119-50 when she has a spell. What could this be?