Author: Morgan Meissner PhD
Stress, hormonal changes, and certain types of foods can all trigger migraine attacks. Some people with migraine find that environmental conditions, including air quality, also affect their symptoms.
For people living with migraine, identifying triggers that cause migraine episodes can be a helpful way to minimize the disruptive nature of the condition.
In this article, we examine the role of pollution in migraine, including how it may trigger attacks and what people can do to prevent them.
With more and more of the world’s population living in urban areas, there has been increasing interest in the effects of air pollution on human health, including migraine attacks.
Compared with other aspects of health, such as heart and lung diseases, the role of pollution in migraine is less clear.
Studies that researchers carried out in Taiwan and South Korea found that higher levels of certain types of air pollutants — tiny pieces of chemicals called particulate matter — were associated with an increase in the number of people seeking medical care for migraine, particularly during warm periods.
The Taiwanese study found no link between air particulate matter levels and migraine during cold temperature days, though. The South Korean study also found that the association between migraine risk and particulate matter levels was weaker on low temperature days.
In contrast, a Boston-based study found that higher levels of air pollution were associated with an increased likelihood of having a migraine headache only during colder months: October through March.
However, this study specifically looked at the link between migraine and traffic-related gaseous pollutants — such as carbon monoxide and ozone — rather than particulate matter.
These results suggest that although air pollution may trigger migraine attacks, this effect is likely dependent on both the type of air pollution and the air temperature.
The researchers did not directly examine the cause of the temperature effects, but they speculate that these are related to other factors that increase the likelihood of migraine episodes, such as humidity or air pressure.
Weather-associated behaviors that affect a person’s exposure to pollutants, such as having the windows open or being outside, could also have an effect.
Can air pollution cause migraine?
Some research also suggests that exposure to gaseous air pollution may increase the likelihood of developing migraine in the first place.
In a 2021 study involving more than 360,000 people in Northern California, long-term exposure to elevated levels of nitrogen dioxide and methane was associated with 2% and 4% increased odds of having migraine, respectively.
Particulate matter exposure did not appear to increase the likelihood of developing migraine.
Although research on the role of pollution in migraine attacks is limited, some experts believe that oxidative stress may be to blame.
Oxidative stress occurs when reactive oxygen species accumulate in cells, and the body’s antioxidant defense systems do not properly clear them. Oxidative stress causes chemical changes in the brain that may increase the sensitivity and excitability of neurons, which can lead to a migraine attack.
All of the major types of air pollutants, including both particulate matter and gaseous pollutants, can cause oxidative stress, but there is a lack of evidence to support a direct relationship between air pollution, oxidative stress, and migraine.
Migraine experiences can vary, but there are some common trends in symptoms, triggers, and treatments. The studies above suggest that although air pollution might contribute to migraine attacks, it is not the most common trigger.
If someone suspects that air pollution may be triggering migraine, they can try keeping a headache journal to track their migraine symptoms and the possible triggers.
People can use services such as AirNow from the Environmental Protection Agency (EPA) to track air quality and the levels of various air pollutants, including ozone and particulate matter.
If air pollution does seem to be a trigger, people can take steps to avoid a migraine attack by:
- limiting their time outdoors
- keeping windows closed
- using an air filter to improve indoor air quality
As many as one-third of people with migraine believe that changes in the weather or other environmental factors trigger some of their attacks, according to the American Migraine Foundation. Some examples of other possible environmental migraine triggers include:
- air pressure
- strong winds
Research exploring the connection between migraine and pollution is still limited. There remains a lot to learn about the potential link, but a few studies have found a connection between air pollution and migraine attacks.
Some people with migraine may find that their symptoms appear or worsen on exposure to high levels of air pollution, including both particulate matter and gaseous emissions.
For these people, tracking air quality and taking steps to limit the time spent outdoors may help prevent migraine attacks.
If migraine symptoms persist despite reducing exposure to pollution, other environmental triggers might be responsible. A headache journal can help a person keep track of their symptoms and triggers. It may be helpful to share this information with a healthcare professional when discussing migraine attack triggers.