Another cause of migraines are food intolerances. We tend to develop intolerances to the foods we eat the most of (or rather TOO much of) -- in the west, that's often wheat or gluten, sometimes corn, rice, dairy, soy or other ubiquitous foods. If you have other symptoms, such as periodic bloating, insomnia, gas, heartburn, skin blemishes and other chronic annoyances -- but headaches and migraine are the biggest clue -- you might have a food intolerance.

An allergy rotation diet can help you pinpoint if and what you may have a reaction to. Start with the common ones; completely eliminate all of a food, including byproducts and derivatives found on food labels, for 7 days. (Exception: dairy takes 21 days.) If you feel worse before you get better, that's probably it. If you experience no change, move on to the next food. The most likely candidate is the food you eat every day and experience the most mental resistance to cutting out.

This may not be it for you, but for folks who do find it as the source of the cause of their migraines, the cure is permanent as long as you don't eat that food. And many people with food intolerances can eat that food occassionally after a period of detoxification and overall improved diet. YMMV.