When i eat chocolate, i get a headache. why is that?

Uncertain: Although chocolate has often been implicated to be a trigger for migraine (usually a throbbing one associated with nausea and occasionally preceded by visual disturbance), many experts feel that the craving for chocolate is part of the migraine march. On the other hand, chocolate does contain a stimulant which may potentially worsen a stress-induced headache. I don't have a clear answer however.