The nature of the onset of migraine is not yet fully known. Especially frequent provoking factors are considered to be emotional stress, mental overexertion, weather change, hypoxia, pulsating light.
Migraine attacks today are considered as a consequence of a disorder of vasomotor regulation due to regional angiodystonia. The eye form of migraine (with aura of visual disturbances) is caused by discirculation in the region of the posterior cerebral artery; its retinal form is probably associated with transient ischemia of the retina.