Some people also experience gastrointestinal symptoms such as nausea, constipation, or diarrhea. Although symptoms in the prodrome vary widely, each person usually has his or her own specific set of symptoms that signal a migraine. The aura phase immediately precedes or accompanies an attack. Migraines with visual disturbances are called classic migraines. The most common aura is flashing lights in a her- ringbone pattern.
Some people see bright lights in other geometric patterns, or half of their visual field is blank.
Others may experience difficulty speaking, weakness on one side of the body, or numbness or tingling in a hand or arm or on one side of the face. Common migraines typically last longer and occur more often than classic migraines. The typical migraine headache is throbbing, with pain starting on one side of the head and then spreading to both sides. The onset is gradual, with the pain increasing in intensity for the first 30 minutes to 2 hours, then leveling off and slowly subsiding. The average duration of the headache phase is a day, but it can last for up to 3 days.