Common Triggers For Migraines

Living with migraine is challenging

Migraines can cause individuals intense pain and nausea. Other common migraine symptoms include light and sound sensitivity. People with migraine also typically are hypersensitive to smell. This is because the migraine brain is intrinsically different – it is more reactive to stimuli than normal.

Migraine is a neurological disorder. We have an ever-increasing understanding of how it occurs, and this is greatly needed to develop more effective treatments. It is however a complex disorder that is not the same for everyone. What can be helpful though is understanding some common triggers for migraines that many people experience.

While all these triggers are commonly experienced, it depends on what the threshold of the brain is at the time as to whether a migraine will be experienced. Sometimes it is when several triggers are occurring together that a migraine will be experienced. Also, it may depend on how recent the last migraine was, as to whether a migraine will be triggered by a stimulus such as alcohol or sleep deprivation for instance.

The two main points to know about triggers are:

The migraine brain is hyperexcitable so things that most people are fine with are not fine if you have migraine


The migraine brain doesn’t like change!

Understanding Triggers for Migraines


Lack of sleep or disrupted sleep is one of the top three triggers for migraine. This takes various forms. We think now that one of the major reasons that sleep deprivation triggers migraines is that the waste disposal system of the brain, the glymphatic system, works best at night. So, if you don’t sleep enough, your brain is not clearing a lot of waste molecules that it should be. These molecules are then found in higher concentrations in the brain, and worsen the hyperexcitability of the neurons, making a migraine much more easily triggered. Only 10% of the glymphatic flow that is meant to occur happens during the day, so sleep is critically important for our brain health.

Our migraine brain doesn’t like change. It likes us to go to bed and wake up at the same time every day. When we sleep in on the weekend because we have not been sleeping during the week, we can trigger a migraine. We are not sure exactly why this occurs, but we know that the hypothalamus is probably playing a role. The hypothalamus is a small part of the brain that regulates many bodily systems through hormones. It is abnormally triggered up to 48 hours before the onset of any headache in a migraine. It is involved in complex networks controlling appetite, thirst, sleep, growth and many other processes.

The more migraines you have, the more it is important to try to get enough sleep, and try to have a regular sleep pattern.

If we have trouble sleeping, it can be because our Circadian rhythm is often disrupted by modern life. It has been shown that a few minutes of direct sunlight in the morning (so that bright outside light hits the retina), can help regulate the Circadian rhythm, and can help normal melatonin production so that we feel sleepy at night. If possible, we should avoid napping during the day so that there is enough “sleep pressure” at night and avoid using alcohol as a sleep aid. While this may seem to help us fall asleep, the resulting sleep quality will be poor. Another issue is that the blue light emitted by screens such as computer screens or phones can make it difficult to fall asleep. Avoiding screen use before bed is advisable.


Stress is often a trigger for migraine, but it can be a lot harder to define than other triggers. Sometimes it is only after a migraine occurs that you realise you have had a busy week, or a lot going on at work. It is rare that a single stressful event such as an argument immediately causes a migraine – although some people do experience this phenomenon from time to time. A common pattern that we see is that some people experience migraines exclusively on the weekends, or the first day of holidays. It is as though the body knows it has to get through the week, but when it relaxes, the migraine hits. Teachers are the classic group of people who experience this. Eventually though, the migraines often break through and start occurring during the week if we are not careful. Some people find that when they retire from a stressful job, their migraines are much better controlled. Like everything with migraine though, everyone’s experience of the disease is different.

We know that the hypothalamus is involved in the first phase of migraine – often called the “premonitory phase”. When we think about a hormone that is released when a person is “stressed” i.e. sick with infection, is being chased by a woolly mammoth, or has an assignment due tomorrow we think about the “stress hormone” cortisol. We can see how sudden spikes or changes in this hormone can trigger a migraine. Again, it may be the sudden changes that are the trigger rather than the level of cortisol itself. We know that people with underlying medical conditions that mean they are dependent on steroids (such as prednisone) don’t produce their own cortisol from their adrenal gland very well, and when they are sick their own adrenal gland’s function is suppressed and they have low cortisol levels. People in this situation can have severe headache and nausea as one of the early signs of low cortisol and usually have a plan that they need to take extra steroid when they are sick to avoid this.

“Stress” is something we all experience, but chronic stress can also be linked to other mental health issues, and there are multiple biochemical pathways likely to be involved. Also, stress can cause us to behave in ways that probably are unhelpful when we have migraine – we may drink alcohol to relax, eat high carbohydrate foods and we may have poor sleep because we are worrying or replaying thoughts in our heads at night.

Stress is also one of the more difficult aspects of migraine triggers to manage as often we don’t have control over the sources of stress. We can’t magically make a sick family member better, make a horrible boss disappear or get through our exams without studying. But being aware that this is a difficult season can help us be aware that we are at greater risk of migraine and think about the triggers we do have more control over. We can also try some strategies to cope with stress such as mindfulness and meditation and talk to a professional if there is anxiety or low mood as well.

Food triggers – Triggers or part of the premonitory phase?

This can be one of the trickiest triggers to work out. Foods can certainly act as migraine triggers. But sometimes what we think is a trigger is in fact an association – it is part of the premonitory phase of the migraine. When we say that the hypothalamus is activated 48 hours before the headache phase of the migraine, what also happens is that the hypothalamus activation is involved in cravings for food and water. As a result, some people in this phase will crave foods such as chocolate, or other sugary food – it is not surprising that people will then think it is a trigger. Often though, a migraine doesn’t occur every time they eat chocolate. Confusingly, chocolate can be a trigger though for some people – it is more likely to be a real trigger when a migraine occurs every time it is eaten rather than occasionally. Like all triggers, it can depend on the migraine threshold. If there is stress and sleep deprivation, then a food is more likely to trigger a migraine– but on a good day, perhaps it will not. Foods such as blue cheese; alcohol such as red wine; and additives such as MSG are classical triggers for many people – but certainly not all. Food triggers can be very specific – sometimes citrus can be a trigger, sometimes dairy products for others – usually people have worked this out themselves. Increasingly we think that there can be a benefit from reducing sugar and refined carbohydrates, and gluten from the diet in a group of people. There are small studies showing an improvement in headache control with a ketogenic diet. A good start is to keep a food diary for a few weeks and see whether any patterns can be seen.

Because the migraine brain doesn’t like change, it doesn’t like wild fluctuations in blood sugar levels, and so skipping meals or fasting can be a trigger for migraine in many people. This can be worse if, when you finally eat, you are so hungry you eat a highly-refined carbohydrate load, spiking your blood glucose, releasing insulin and then potentially going low again. Having access to snacks during the day if you are busy, and eating smaller meals, with high GI foods, enough protein/fat to keep you full and avoiding excessive sugar is a strategy if this is something you experience.

Likewise, forgetting to drink enough water (or other non-alcoholic beverage) is a common trigger. One of the main reasons we get a hangover is that alcohol causes significant dehydration and triggers a migraine-type headache.

Caffeine is another complex trigger. Caffeine taken at the beginning of a migraine can actually be helpful, and is a good hack to know if you are out and about and don’t have any medications with you. Caffeine with ibuprofen or aspirin probably has a synergistic effect and in some countries combination tablets are available which contain caffeine for this reason. If you drink 1-2 cups of coffee, particularly in the morning, then this is usually fine for most people. Interestingly, for people with migraine, if they don’t drink their usual morning coffee, they can have a caffeine-withdrawal headache. This can be a contributing factor to the migraines triggered by sleeping in as well. Obviously, caffeine too late in the day interferes with sleep (even if you don’t think it does) and more than four standard coffees per day, and the equivalent in energy drinks/soft drink/tea, can cause rebound headaches. Also it is worth knowing that some take away coffees contain a lot more caffeine per drink than a normal household-made coffee – a Starbucks coffee for instance should count as two coffees in the total daily count.

You can see how these triggers can be inter-related. If you don’t sleep you are tired the next day, then have more coffee to get through the day, then feel tired when the caffeine wears off, and have a quick nap, then feel more tired, then have another coffee, and then can’t fall asleep….. Add some stress to the mix and it’s no surprise that the brain is firing off all over the place.


The migraine brain does not like change. Hormonal fluctuations are why we see a big peak in incidence of migraine in adolescence for both girls and boys, and why perimenopause causes worsening severity of migraines in women, followed frequently by significant reduction in migraine frequency after menopause. Pregnancy too, with its wild fluctuations in hormonal levels, can cause migraines in people who have never had them before, worsening of migraines in people with only occasional ones, and also strangely an improvement in migraines in some others.

Migraine is far more common in women than in men, and the monthly hormonal fluctuations of the menstrual cycle if probably the major reason for this. While men have fluctuations in their hormones as well, this is not as extreme and is on a more daily cycle rather than monthly. One would think that hormonal contraception would fix this issue by evening out hormonal levels, but in fact exogenous oestrogen can be a significant migraine trigger in some people. It is good to be aware that hormones are a factor in migraines, but realistically it can be very difficult to manage.


The other trigger that is non-modifiable is the weather. In large surveys of patients it is listed as the most common trigger and initially it seems difficult to understand why this would be the case. Again, it seems to be that the trigger is not the weather itself, but the change in barometric pressure that precedes particular types of weather that the brain is responding to. In Northern Australia, this is typically the change in barometric pressure that precedes an afternoon storm in summer. For some people, rainy, drizzly weather is the trigger, again probably due to barometric pressure changes. In the Northern Hemisphere, snow can be the trigger for the same reason. It may also be one of the reasons that people are often triggered by plane flights – although there are usually quite a few additional triggers on planes with associated poor sleep, smells, and sometimes stress, as well as the pressure changes with taking off and landing.

Bright lights, sounds and smells

This is another issue of trigger vs premonitory phase. Prior to and during the headache phase of the migraine, people with migraine are more sensitive to environmental stimuli because the brain doesn’t have the same ability to dampen down its responses compared to non-migraine people. This is why people having a migraine often prefer to lie down in a dark room, ideally quietly, as stimuli are very aggravating. In this phase, smells such as meat cooking, cleaning chemicals, perfumes and petrol are even more irritating than usual and can appear to be triggers – but often the migraine is already occurring.

Certainly though, all of these can also be triggers – probably worse when the threshold is already low. Glare when driving – particularly when light hits the eye from the side is a classic trigger. For some people noisy environments (hello teachers again) are triggering – supermarkets are classically terrible places for people with migraine as they are noisy, very brightly lit and colourful, and there are many smells.

Smells are tiny, aerosolised chemicals or compounds that are inhaled, and are detected by specialised nerve cells in the olfactory epithelium at the top of the nose – these nerve cells are very close to the brain, and this is why in some people smelling a strong perfume can seemingly trigger an instant headache.

While this whole area is complicated, it is worth understanding the factors that may be involved in your own migraines. Contact us if you would like help with identifying your individual triggers and working out a plan to de-escalate your migraines.

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