Some people with migraines report warning symptoms. This is known as migraine with aura. Warning symptoms may include blurred vision, seeing “stars,” or other odd sensations like unpleasant smells before the onset of an attack. Affected people may even experience slurred speech or other language difficulties. Temporary loss of vision in one eye has also been reported.
Aura may occur from 10 minutes to one day before onset of a migraine. In some cases, a person may experience an aura without having a migraine. Migraine with aura tends to be less severe and disabling than migraine without an aura.
A number of factors are known to trigger the onset of migraine episodes. More than half of people who experience migraine with aura report having at least one trigger for their migraines. Potential triggers are numerous and may include:
• fluctuating hormone levels (especially among women, and boys going through puberty)
• stress or anxiety
• fermented and pickled foods
• cured meats and aged cheeses
• fruits such as bananas, avocados, and citrus
• skipped meals
• too little or too much sleep
• bright or strong lights
• fluctuations in atmospheric pressure due to changing weather
• drinking alcohol
• caffeine withdrawal
—Healthline