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Friends enjoying a beer outside - the drink being a controllable migraine trigger

Understanding my Migraine Attacks: Triggers vs. Thresholds

Reading time | 4 mins

When I meet someone new and they find out I live with chronic migraine, one of the first things they always ask is whether or not I know what triggers my attacks. Since this is usually someone I am just getting to know, it’s not the time to get into the nitty-gritty so I usually just laugh and say: “Life,” and try to move on. Unfortunately, this is often followed by a well-meaning, but rather unhelpful comment along the lines of: "Oh, my sister finds they are caused by cheese. She avoids cheese now and she’s fine.”

Here’s where I smile politely and say that I'm glad their sister has found such an easy solution for their migraines. The truth is that for many people migraine is often more complicated and for me, 'life' as a trigger really does sum it up best.

Triggers are more complicated than you think 

I suppose the thing that bothers me when people talk about 'migraine triggers' is when they assume that if I were to avoid these triggers, my migraine attacks would stop. If only it were as simple as that!

To me, triggers indicate the start of a migraine attack, and not necessarily the cause of it. To someone who doesn’t suffer from migraines this may seem like an overly subtle difference, but for those of us who do, it’s very important.  A migraine trigger to me is like a starting pistol firing... the beginning of the prodrome or ‘pre-headache’ symptoms. Obviously migraines don’t usually start as suddenly as a firing pistol, but a trigger, to me, is the signal that a migraine event is kicking off.

What is a threshold and how does this affect triggers?

My defining moment in understanding the cause of a migraine came when my Headache Clinic nurse explained thresholds to me. She explained that a migraine is not usually caused by just one thing, but rather by a combination of factors.

She had me picture a chart with a horizontal line across it, representing my migraine threshold.  If my resistance fell below that threshold, then a migraine could develop.

Some things may only have a very small effect, like a change in the weather for example. Others can have a much larger effect on my migraine resistance, such as stress.

Cheese clearly has a large resistance effect for my well-meaning acquaintance’s sister. For her, cheese might cause a big enough resistance to take her below that threshold, but she might also find that an accumulation of other things will take her there too. Conversely, when her resistance is high she might be able to eat cheese without getting a migraine.

Why the trigger/threshold distinction can help

Ever since I’ve learnt this important distinction between triggers vs. thresholds, I have been able to gain a much better understanding of what causes my migraine attacks.

I know, for instance, that around the time of menstruation and ovulation, the hormonal change means that my resistance is already near the threshold line and it may take something as minor as glancing at a bright screen to take me below it.

By keeping very detailed headache diaries, it is possible to start identifying how much of an impact different things have upon the condition.  Although we don't get a handy individual chart in real life, when you see the same things come up again and again, you can start to understand your own migraine causes better.

Planning around your threshold

I use this knowledge to plan for things.  When I'm going away on a trip or going to a big event, I do everything I can to make sure that my resistance is as high as possible.  There are many contributing factors that are out of my control of course, but I try to manage what I can so that none of the individual triggers lower my threshold.

Looking at the picture in a more holistic way like this has meant that – for instance – after having to abstain from beer for years because a beer always seemed to cause a migraine attack, I can now enjoy the occasional brew because I can better assess where I am in relation to my migraine threshold.

Sometimes I get it wrong of course. Then I kick myself for having to endure a migraine attack because I indulged in a glass of beer, but more often than not I get it right and then I savour every sip when I do.

The takeaway

When I say to people who ask, that 'life' is what causes my migraines I really do mean it: there are a thousand different things in each day that chip away at my resistance and push me below that migraine threshold – some just have a bigger impact than others.

Most importantly? Thinking like this helps me to control my own migraine experience as much as possible. 

NPS-IE-NP-00367 December 2021