Migraine is a type of severe headache that starts suddenly. The pain in the head is usually pulsing, it touches one side of the head, but sometimes it happens to involve both sides. About 10 to 30 minutes before the onset of headache about 20% of people have symptoms of depression, irritability, restlessness, nausea or loss of appetite. So many people lose vision in a specific area or see a blinking or sparkling light.