About half of people with fibromyalgia also have carb intolerance or the more intense Hypoglycemia. If you have fibromyalgia, it will be a great help to you to do the HG diet for a month to see if it helps some of your symptoms. HG symptoms and fibro symptoms overlap, so you could be totally clear of fibro symptoms, but still have HG symptoms.
The symptoms of HG can vary from person to person. Some people have it so severe that they have to be watched because they can pass out from it. Check out my post on Hypoglycemia for a long list of the symptoms.