Attention, migraine sufferers: TIME reports that common environmental factors which you thought cause those debilitating headaches may not actually be the main triggers but the symptoms.

This is according to a recent study featured in the journal Neurology, which explored the potency of commonly thought instigators, such as bright lights and too much exercise.

Foregoing the common practice of surveying migraine sufferers, scientists worked with 27 volunteers and placed them in a laboratory setting, where they were asked to either run or pedal an exercise bike with full effort, while being exposed to bright and flashing lights for 40 minutes. Interestingly, only three patients (or 11 percent of the total number of participants) experienced migraines with auras, which included symptoms such as seeing blind spots, zigzag patterns, and hallucinations. On the other hand, three persons experienced migraines without auras.

According to Dr. Stephen D. Silberstein, professor of neurology at the Thomas Jefferson University and director of the Jefferson Headache Center, popular triggers may in fact already be the beginnings of a migraine. He explains, “You eat chocolate and you get a headache. Does that mean chocolate triggers the headache? What probably happens is the first symptom of your migraine attack is the desire to eat chocolate. Just like when you’re pregnant, you might want pickles or ice cream. That’s one end of the spectrum, where the desire to do something is part of the migraine attack, not the trigger.”

This is not to say that exposure to bright lights and over-exercising won’t cause migraines. Triggers and symptoms are different for everybody, and it may take a lot of self-observation to differentiate one from the other. In the long run, searching for the real causes may be worth the effort.

(Photo by Daniel Oldfield via Flickr Creative Commons)