Preliminary visual distturbance & cortical symptom at onset of attack are due to Vasoconstriction of branches of internal carotid artery. Vasodilatation in distribution of external carotid artery.

Hi.... It could be an migraine headache.... Self-care measures can help ease the pain of a migraine headache. Try muscle relaxation exercises. Relaxation may help ease the pain of a migraine headache. Relaxation techniques may include progressive muscle relaxation, meditation or yoga. Get enough sleep, but don't oversleep. Get an adequate amount of sleep each night. It's best to go to bed and wake up at regular times, as well. Rest and relax. If possible, rest in a dark, quiet room when you feel a headache coming on.