Migraine triggers: what really sets off an attack and what we have made up

Sunday lunch, pudding on the table. “Not for me, thanks. Chocolate sets off my migraine.” Someone at the table nods, someone else says that for them it is red wine, a third swears by the weather. Soon there is a whole list on the table: cheese, coffee, not enough coffee, citrus fruit, strong smells, a change in air pressure, too much sleep, too little sleep, the flickering light in the office.

People with migraine know this list very well. Many carry it with them for years, add to it and arrange their lives around it. They give up food they love, turn down invitations, choose jobs by the lighting. And many feel that every time an attack comes, they must have done something wrong.

In this post I would like to look at what we really know about migraine triggers and where we have built the stories ourselves — not because people are naive, but because our brains are very good at finding causes even where there are none. And because how we deal with triggers is largely a psychological question, this part is my field too.

First: migraine is not the result of bad choices

Migraine is a neurological disease. It is not a psychosomatic symptom and it is not a punishment for a piece of cheese or a sleepless night. The brains of people with migraine are differently sensitive to change — in internal rhythm, hormones, sleep, food, workload. Genes play an important role in this. A doctor makes the diagnosis and leads treatment, a neurologist where needed; in this post I will not recommend any medication.

I stress this because talk of triggers very quickly turns into talk of guilt. If chocolate triggers your migraine, then it is your own fault for eating it. If stress triggers it, then you should simply worry less. That logic is unfair, and it is also wrong. A trigger, even when it really works, is not the cause of the illness. At most it is the last drop for a brain that is already primed for an attack.

What people name as triggers

One of the most frequently cited studies on triggers is an American study by L. Kelman from 2007. It surveyed more than seventeen hundred people with migraine and found that roughly three quarters named at least one trigger. Stress was mentioned most often, followed by hormonal changes in women, skipped meals, weather and disturbed sleep, then smells, light, alcohol, smoke and others.

The study is important, but it tells us exactly what it says: what people report. It does not tell us what actually sets off an attack. Those are two different questions, and the gap between them is the heart of this post.

Why it is so easy to get it wrong

Imagine you have a few attacks a month. After each one you ask yourself: what did I do differently yesterday? You will always find something. Yesterday was a demanding day, or you ate something you don’t often eat, or the weather changed. Because every day brings dozens of changes, there is always a candidate. The days when you did the same thing and had no attack you do not remember, because nothing happened to remind you of them.

This is called confirmation bias. It is not a sign of stupidity — every brain works this way, especially around something that hurts and that we fear. Finding a cause gives us a sense of control. And with an illness that arrives unannounced, a sense of control is very precious.

Add to this something we were unaware of for a long time. A migraine attack does not begin with pain. Hours or even a day before it, there can be a premonitory phase: tiredness, yawning, irritability, sensitivity to light, neck tension and — in some people — cravings for particular foods, often sweet ones. Brain imaging studies show that during this time parts of the brain such as the hypothalamus are already behaving differently.

This means the story “I ate chocolate and got a migraine” may in fact run the other way round: the attack had already begun, and the craving for chocolate was one of its first signs. The same goes for sensitivity to light — the light that “triggered” you may simply have bothered you more because your brain was already on its way into an attack.

What experiments show when a trigger is actually tested

When researchers test a supposed trigger under controlled conditions, the picture is often more modest than the Sunday-lunch list.

In a double-blind chocolate experiment from 1997, participants did not know whether they were eating chocolate or a similar product without it. How often headaches occurred did not differ meaningfully between the two — even in people who were convinced chocolate set off their attacks. In a Danish study from 2013, people with migraine with aura were deliberately exposed to triggers they themselves had named as reliable, such as flickering light and exertion. An attack followed in only a minority.

This does not mean triggers do not exist. It means they are a good deal less reliable than we think, and that in the same person the same factor “works” one time and not the next. Some factors are better supported by research than others: changes in sleep rhythm, skipped meals, the drop in oestrogen before menstruation in women, and stress — including the curious pattern in which the attack often arrives only once the stress eases. There is more on that in Stress and migraine: why the attack often comes only after the pressure. For alcohol, weather, smells and individual foods, the evidence is more mixed and depends heavily on the individual.

The threshold model: why the same glass is enough one time and not another

How can we make sense of the same factor triggering an attack one time and not another? Specialists often use the image of a threshold. At any given moment, the brain of a person with migraine has a certain level of readiness for an attack. That level fluctuates — it depends on the hormonal cycle, on how long it has been since the last attack, on an internal rhythm we do not yet fully understand. Factors such as poor sleep, a skipped meal or a hard week pile on top of it.

When the threshold is low, a little may be enough. When it is high, even several factors together do not lead to an attack. That is why a glass of wine “works” at one celebration and not at another. And it is why strictly avoiding a single factor is often disappointing: the attacks keep coming without it, because it was only one of many.

The threshold model is not an exact picture of the brain — it is a simplification. But it is useful, because it replaces the question “what did I do wrong?” with a more practical one: “what has built up, and which of it can I change, even a little?”

The cost of avoidance

When someone believes an attack can be brought on by anything, they start to avoid. First chocolate, then wine, then celebrations where there is wine. Then shopping centres because of the lights, the cinema, long drives, drinks after work. Life slowly narrows, and the attacks often do not go away.

The Australian psychologist Paul Martin noticed this years ago and proposed a shift: with headache triggers, to think about coping, not avoidance. His reasoning draws on what we know from anxiety and pain: long-term avoidance of a stimulus can increase sensitivity to it, while gradual and controlled exposure can reduce it. Some factors, such as stress or light, cannot be avoided anyway. With others, such as skipped meals or irregular sleep, the opposite makes sense — not avoidance, but regularity.

Here we meet psychology that does not need to be reinvented. I describe the mechanism by which avoidance calms you today and increases fear tomorrow in Anxiety and avoidance: why avoidance helps you today and hurts you tomorrow. With migraine it is more complicated still, because the pain is real and an attack can be genuinely severe. So this is not work you do on gut feeling, but — where food, medication or bigger changes are concerned — in agreement with your doctor.

How it sounds in a relationship

Triggers do not live only in one person’s head. They quickly become family rules. A short example (composed, not a real person):

“We can’t go to any party any more. There’s always something — the music, the perfume, it’s too late.”
“I’m only trying to protect myself. You don’t know what the next day is like.”
“I do. But last time we stayed at home and you got it anyway.”
“And now you’re going to say I made it up?”
“No. I’m saying I’m scared we’ll end up staying at home for everything.”

Nobody in this conversation is to blame. Both are right. The person with migraine knows how bad the next day is and is rightly protecting themselves. The partner notices how their shared life is shrinking and is right to say so. The trouble starts when talk about triggers turns into talk about whether the pain is “real” — then both feel misunderstood. In relational family therapy this is often exactly what we look at: how an illness starts to organise a relationship, and how a couple can talk about it without one becoming the patient and the other the supervisor.

Exercise: from a list of prohibitions to a list of experiments

This exercise is for those who have a long list of triggers and the sense that it is limiting their life. Where food, medication and changes to treatment are concerned, check with your doctor first.

1. Write down your list. Everything you avoid because of migraine. Next to each item, note how long you have been avoiding it and why you first concluded it was a trigger — one attack, several attacks, someone’s advice, something you read online.
2. Sort it into three groups. Factors worth regulating (regular meals, similar sleep times), factors you cannot avoid (weather, the menstrual cycle, stress at work), and factors you are not sure about (particular foods, drinks, places, events).
3. With the first group, start with regularity, not perfection. The goal is not never to miss a meal, but for skipping meals not to be the rule. How to sort out sleep without it becoming a new worry is described in What sleep hygiene is — and why on its own it often isn’t enough.
4. With the third group, choose a single item to test. One that matters most to you and where there is no medical reason not to. Try it in a small amount on a day when you are rested, fed and otherwise in good shape. Note what happened — one test will not give you proof, but a few will give you a picture.
5. With the second group, replace avoidance with coping. For stress that means planned breaks and relaxation techniques such as progressive muscle relaxation; for weather and the cycle it means consciously reducing other demands on harder days.

For systematic recording — when an attack comes, what happened before it and what did not — the most useful tool is a diary that you also show your doctor. How to keep one without it becoming a new obsession is covered in A migraine diary: why it works and how to keep one. For more general tracking of links between body and mood, the knowledge base has the diary of bodily signs.

Where this view does not apply

I would not want anyone to read this post as “triggers are made up”. They are not. In some people the link between a particular factor and an attack is clear and repeatable, and then avoidance is reasonable. In women with menstrual migraine, the link with the hormonal cycle is well described, and treatment builds on it too. Caffeine and alcohol also affect sleep and mood in many people, so it makes sense to keep an eye on how much you drink — more on that in Caffeine, alcohol, screens and sleep: everyday amplifiers of anxiety.

Nor does this post apply to a headache that changes in nature. If attacks suddenly become more frequent, change character or come with new symptoms, or if a headache appears after a fall, with fever or as the worst headache of your life, that is not a matter of triggers but of a doctor — in an emergency, call 112 (the emergency number in Slovenia) straight away. Frequent use of painkillers can itself keep headaches going, which a doctor needs to assess.

And finally: testing triggers is not for everyone and not for every moment. If your attacks are very frequent or very severe, the first step is to see a doctor and perhaps start preventive treatment, not experiments with chocolate.

What psychotherapy can contribute

Psychotherapy does not treat migraine. It can, however, help with how a person lives with migraine. Research supports behavioural approaches such as relaxation training and cognitive behavioural therapy as a complement to doctor-led treatment. Part of that work is exactly what I write about here: telling apart the factors worth regulating from those that have become nothing more than a source of fear.

In conversation, things often come up that are not written on any list of triggers. Guilt towards a partner or children over cancelled plans. The belief that you must control everything because the illness itself is so uncontrollable. Chronic stress that nobody sees, because the person carries it quietly. And family stories about illness — how pain was talked about, or whether it was talked about at all — which we carry into our adult relationships. People who have learnt that others do not believe their bodily symptoms may also recognise themselves in “The tests are normal, but it still hurts”. I also see English-speaking clients in person in Ljubljana.

What to remember

• Migraine is a neurological disease. A trigger, even when it really works, is not the cause and not proof that you did something wrong.
• Roughly three quarters of people with migraine report triggers, but experiments show they are far less reliable than we believe.
• Craving sweets, light sensitivity or yawning can already be the first signs of an attack rather than its cause.
• Factors add up, and the threshold fluctuates. That is why the same glass of wine “works” one time and not the next.
• Regularity (sleep, meals) and coping are often more helpful than an ever-longer list of prohibitions. Agree any changes to food and medication with your doctor.