this is a vascular headache associated with changes in the size of the arteries within and outside of the brain. a migraine begins when hyperactive nerve cells send out impulses to the blood vessels causing constriction followed by the dilation of these vessels and the release of prostaglandins serotonin and other inflammatory substances that cause the pulsation to be painful. migraine is a genetic disorder that is inherited. a migraine causes mild to severe pain and lasts from four hours up to a week. migraines usually occur two to four times per month.
what is a migraine?