Migraine triggers
Migraine attack triggers
Understanding migraine triggers is important for both people with migraine and the health professionals who treat them.
Most migraine triggers relate to changes in the external environment or within the body itself. Maintaining routines as much as possible can help keep the migraine brain in equilibrium.
However, every person with migraine has different triggers. Every person with migraine also has a different threshold for experiencing a migraine attack.
Another complication is that many factors thought to be triggers are actually part of the prodromal phase of migraine, so may be a warning sign and not the cause of an attack. Many health professionals now advise against spending a lot of time trying to identify triggers, as this hasn’t proved to be an effective way to prevent migraine attacks.
Thresholds for migraine attacks and prodromal symptoms
The idea of a migraine threshold can help explain why a some things appear to trigger a migraine attack but not always. Some people have a low threshold, and even a small exposure to one trigger can set off an attack. Other people have a high threshold, and it takes multiple factors in combination to cause an attack.
This can make it difficult to identify the definitive cause of an attack. For example, a person with migraine may drink a glass of wine one night and have no ill effects. Another night, when they are stressed from work and are just starting on their period, a glass of wine may be the factor that tips them over their threshold for a migraine attack.
An individual’s threshold can also change over time. The goal of preventive treatment is to raise the migraine threshold, so that attacks are less likely to occur.
It can sometimes be difficult to tell if something is really a trigger, or if what you’re experiencing is an early symptom of a migraine attack. Some prodromal symptoms previously thought to be triggers of migraine attacks, like eating certain foods, are now considered to be part of the attack itself. For example, during the prodrome phase you may crave something sweet, like chocolate, which you eat, and then a few hours later you develop a headache. You may assume the chocolate caused the migraine attack, however, the attack had already started before you ate the chocolate.
The anxiety around restricting and monitoring the diet and the environment and avoiding potential triggers can worsen quality of life and severity of attacks. Instead of searching for triggers, many headache specialists now advise people with migraine to focus on maintaining a healthy diet, regular eating and sleeping routines, regular exercise and stress management.
Potential migraine attack triggers
Emotional stress is a significant trigger for many people with migraine. A migraine attack can also occur when stress is released, for example, at the weekend or at the start of a holiday.
Hormonal fluctuations, particularly in women, can be a major trigger. This includes menstrual cycles, pregnancy, menopause and the use of birth control pills.
Fasting or missing meals can trigger a migraine attack. The exact reasons are not clear but it may be due to low or changing levels of blood sugar, dehydration or caffeine withdrawal.
There’s a lot of conflicting advice and evidence about dietary triggers.
Dietary triggers that are often cited as causing migraine attacks include chocolate, aged cheeses, citrus, nuts, onions, tomatoes, food containing tyramine or histamine or gluten, processed foods and artificial sweeteners.
However, it’s currently thought that many of the foods that were believed to trigger a migraine attack are actually symptoms and cravings that are part of the prodromal phase.
A couple of exceptions to this are alcohol and caffeine. And if you have a food allergy, of course avoid this food. Some people have a very clear and consistent response to a certain food – again, avoid in these cases.
But for most people, the relationship between eating a specific food and a migraine attack is inconsistent and not causal.
Rapid changes in weather patterns, such as sudden shifts in temperature, humidity or barometric pressure, can trigger a migraine attack.
Environmental factors like smoke or allergens can trigger migraine attacks in susceptible people.
Both insufficient and excessive sleep can trigger a migraine attack. Irregular sleep patterns and jet lag can also be problematic. Having a regular bedtime and regular wake up time – even on weekends – can help.
Intense physical activity, especially if it leads to dehydration, can trigger a migraine attack. However, regular exercise can also help prevent migraine and reduce the severity of attacks. It’s important to build up slowly when starting an exercise programme and seek the advice of a health or fitness professional if needed.
Exposure to bright or flickering lights, loud noises, and strong perfumes or odours are often cited as migraine triggers. However, these exposures may in fact be part of the prodromal phase of migraine. During the prodromal phase, before the headache occurs, many people develop sensitivity to light, sound and smell.
These types of stimuli could be both signs of an impending attack (prodromal symptoms) and also trigger factors, that tip the migraine brain at a low threshold into an attack.
