What is different between headaches and migraines and are migraines dangerous ?

Migraine = Headache+: Migraines are the most common cause of frequent headache in an otherwise healthy individual with a normal neurological exam. If you have an aura (i.e. See flashing lights) prior to the headache, it clinches it, but that is in a minority of people. Often times the headaches worsen due to medication overuse/rebound. Often after a migraine there will be a "hangover" feeling. Generally not dangerous.