The concept of the migraine threshold is integral to the understanding, treatment, and prevention of migraine disorder. As described in more detail below, once you encounter enough migraine triggers to reach your genetically pre-determined migraine threshold, a migraine will occur.
The idea is simple: every person has a genetically pre-determined migraine threshold 3. When the threshold is exceeded, a migraine will occur. One individual can have a relatively low threshold, represented by the lowest red-dashed line on this graph. For this person, it is markedly easier to trigger a migraine; a combination of just a few triggers could be enough to break threshold. Others may have a higher threshold, as represented by the middle and top lines. These individuals can encounter a greater number of migraine triggers before experiencing a migraine.
Imagine the graph below as a hypothetical representation of your average day. As the day goes on, you encounter a number of triggers, each of which adds to your overall trigger load, numbered 1-4:
1| Stress. You’re stressed out about a presentation at work today, and the increase in stress hormones in your brain.
2| Hormones. If you’re a lady, imagine you’re on your period and your hormone levels are fluctuating.
3 | Allergies. It’s spring time and you’re subjected to a number of seasonal allergens. Your allergies cause your body to release histamine, which is a migraine trigger.
4| Sleep Disturbance. You didn’t sleep well the night before– for some reason, you kept tossing and turning, and weren’t able to get quality rest.
Each of these triggers you encountered increased your overall migraine trigger load. You’re now hovering dangerously close to your trigger threshold: in this over-simplified scenario, if you encounter one more trigger, you may break over your threshold.
5| Dietary Triggers. You eat a trigger-laden breakfast of bananas, yogurt, and coffee.
Trigger #5 caused you to break past your trigger threshold. Now, you’ll start to feel symptomatic– you may develop a headache, or feel dizzy, etc. What you feel depends on what pathway the triggers follow in your brain.
Number 6 represents the idea that you will remain above threshold, experiencing migraine symptoms, for some period of time. Once you pass back below threshold, the migraine symptoms will cease.