There is evidence that the migraine aura is due to an electrical or chemical wave that moves across the brain. The part of the brain where the electrical or chemical wave spreads determines the type of symptoms you might experience.

This electrical or chemical wave can occur in areas that process sensory signals, speech centers or centers that control movement. The most common type of aura is visual aura, which occurs when a wave of electrical activity spreads through the visual cortex and causes visual symptoms.

The electrical and chemical waves can occur with normal functioning of the nerves and do not cause harm to the brain.

Many of the same factors that trigger migraine can also trigger migraine with aura, including stress, bright lights, some foods and medications, too much or too little sleep, and menstruation.