I get migraines and caffine does not trigger them it actually helps them...I have to take excedrin because it contains caffine (all brands of excedrin (tension, migraine, and the regular) contain the same ingredients!!)- when you get a migraine the blood vessels get constricted and caffine releases the constriction...BUT you have to be careful with Excedrin - because of the amount of caffine in them you can get addicted ( I DID) and then your body becomes so use to having that much caffine that if you dont continue taking them you get a headache(a regular one not a mnigraine) from not enough caffine...so you cant depend on them but when it feels really bad I take them...