what causes a migraine?
One leading theory for the cause of migraines is âcortical spreading depression.â This wave of brain activity that sweeps over the brain, can be seen on an MRI and is blamed for migraine aura and other migraine symptoms. Others believe hyperactivity in the brain stem causes migraines. Because migraines are difficult to control, many people with this disorder often take medication regularly. Overuse of medication can also lead to migraines.