A migraine does not just restrict itself to a headache. Because it is a disease involving the nervous system of the body, it can lead to dangerous consequences like:
Stroke: Migraine can lead to leakage of blood in the brain resulting in stroke.
Seizure: Migraine can be followed by an episode of fits or convulsions, called as Migraine Seizure.
Status Migrainosus: Occasionally, the attack can be so severe as to last for more than 72 hours. This is called Status Migrainosus
Medication overuse headache: In patients habituated to allopathic painkillers, a headache of a more severe variety occurs when the effect of the medicine wears off.