I'm not sure what I have, hyperglycemia or hypoglycemia. I saw a doctor about it a couple years ago and he listened to my symptoms and what I do to prevent it and he said basically that I'm treating it correctly and running a sugar test on me would only do harm, and to just continue what I'm doing.
My symptoms are I when I eat sugar, say a package of skittles with having had no protein food before it I'll nearly instantly get shaky, nauseaus etc. If I eat protein (chicken/cheese/milk seems to work the best/fastest) I'll nearly instantly feel better. I can have a soda a day, or a dessert a day after a meal and stay balanced, but if I just eat sugar in between meals I get that horrible feeling. Basically protein makes me feel better, sugar fucks me up.
Whichever it is, I can tell you hypo/hyperglycemia forces you to control your eating, you'll invariably get on a better diet then you were currently on and your body will thank you for it. It's almost nice having a bad reaction with sugar sometimes, my pigging out would be the equivalent of 2 donuts, or a candy bar and a soda (which I'd better have a block of cheese on standby for), it doesn't leave you much opportunity to get fat.