Explain the term - Migraine

Perhaps the most common neurological disorder, migraine afflicts some 5% to 20% of the population at some time in their lives. The World Federation of Neurology defines migraine as a "Familial disorder characterised by recurrent attacks of headache widely variable in intensity, frequency and duration. Attacks are commonly unilateral and are usually associated with anorexia, nausea, and vomiting. In some cases they are preceded by or associated with neurological and mood disturbances". There are several types of migraine, including classic migraine, common migraine, cluster headache, and hemiplegic and ophthalmologic migraine.