My 13 yr old boy has had several bouts of dizziness and shakiness in past two weeks. His pulse was 106 when I checked it. He had eaten 30 minutes prior (chicken flautas, more carb than protein). He says he drank water from the water fountain at school, but has not been more thirsty than normal. It is not hot today.

I recall my brother got dizzy and nearly passed out at the same age.