To determine if you have reactive hypoglycemia you go through something called a 5 hour GTT (Glucose Tolerance Test), which is hell if you really do have the disorder. Essentially you fast after drinking a sugary drinks, and they test your blood at intervals to see what it does. A Reactive Hypoglycemic will spike, then crash, unlike a normal person who will have a smaller rise then pretty much stay there. See, she normally has to eat ridiculously healthy food every 2 hours to stay even, otherwise she crashes.

It starts with cold sweats, then degenerates into nausea, confusion and a rotten mood. It never gets that bad with her anymore, we have a good system going now. When she is upset about something the first thing I ask is: when's the last time you ate?

If you want to know more about it, check out her site: http://www.reactivehypoglycemia.info/articles/

A simple finger prick blood glucose check[1] will give the current blood sugar level. A doctor's office can also check A1C level that basically gives a longer term (couple of months) look at what the blood glucose level has been.

1. http://en.wikipedia.org/wiki/Blood_glucose_monitoring