Is Air Pollution to Blame for Your Headache?

Key TakeawaysExposure to air pollutants is associated with a host of symptoms, including breathing troubles and headaches.It’s unclear how air pollutants trigger headaches, but experts theorize it has to do with inflammation and certain nervous system pathways.If you suffer from migraines, keep up with the air quality index (AQI) to monitor your risk.

Key Takeaways

Exposure to air pollutants is associated with a host of symptoms, including breathing troubles and headaches.It’s unclear how air pollutants trigger headaches, but experts theorize it has to do with inflammation and certain nervous system pathways.If you suffer from migraines, keep up with the air quality index (AQI) to monitor your risk.

The air you breathe these days is less than fresh due to pollutants such as wildfire smoke, car exhaust, and industrial fumes, to name a few.

Marilyn Howarth, MD, director of community outreach with the University of Pennsylvania’s Center of Excellence in Environmental Toxicology, told Verywell that strong odors and toxic chemicals may trigger people prone to headaches. Even a chemical that’s smelly but not particularly toxic—think sewer gas—could trigger a severe headache in someone with a history of migraines, she said.

People who regularly suffer headaches described worsening symptoms as wildfire smoke settled over the United States this June, leading to increased awareness of air quality and neurological health. The cocktail of chemicals regularly spewed from traffic and industry can irritate a person’s sinuses and exacerbate headaches, Howarth said.

Breathing in industrial chemicals in the home can also trigger headaches, and air pollution is just one of many environmental factors that can worsen symptoms in people withheadache disorders.

Many Air Pollutants Can Trigger Headaches

Scientists have studied the effects of wildfire smoke exposure on human health in California, where wildfire seasons have grown more intense over the years. In a recent analysis of emergency room data from 2006–2020, researchers found that exposure to wildfire smoke was associated with more headache-related emergency room (ER) visits.

All types of fires release smoke containing carbon monoxide, carbon dioxide, and particulate matter (also known as PM or soot). Depending on the source of the fire, what is burning, and how hot the fire gets, smoke can contain other chemicals and hazardous air pollutants, according to the Environmental Protection Agency (EPA).

The main components of particulate matter include microscopic bits of ammonia, sodium chloride, black carbon, sulfates, mineral dust, and water, saidAnna Pace, MD, aneurologistat Mount Sinai Health System. Research has found that exposure to fine particulate matter (PM2.5) has been directly linked to increased ER visits for migraines in South Korea.

Exposure to “coarse” particulate matter (PM10)—particles up to about four times larger than PM2.5—has also been studied along with other air pollutants in relation to headaches.In Taipei and Seoul, researchers found that increased levels of PM10, carbon monoxide, nitrogen dioxide, and ground-level ozone were each independently associated with increased headache-related ER visits.

When Should You Worry About a Headache?

How Air Quality Triggers Headaches

Experts are still trying to understand how air quality may trigger or exacerbate headaches. Pace said it’s possible that certain air pollutants can trigger the neural pathways involved in themigraine process,or headaches may stem from pollution-induced inflammation in the brain.

If you are someone who is sensitive to odors, your headache is directly stimulated through the olfactory nerves that connect the back of your nose to your brain, Howarth said.

While more research is needed to determine the effects of specific pollutants, there’s enough data out there to take caution if you are prone to headaches. Poor air quality can interact with an underlying headache disorder, she said, so migraine sufferers should take extra care on high-AQI days.

“It seems that the longer the exposure [to air pollutants], the more likely that someone with an underlying primary headache disorder can experience an exacerbation,” Pace said.

She added that physical activity outside in poor air quality—especially for prolonged periods—can also increase the odds of a headache.

Air pollution-related headache symptoms tend to be similar to a person’s typical headache. Pace said that someone who gets migraines may experience the followingsymptomswith air pollution-induced headaches:

You might not be able to pinpoint air quality as the definite cause unless you rule out other triggers, such as light, sound, and food, Pace added.

What Can the Air Quality Index Tell You?

Exposure Effects May Be Stronger On Hot Days

Studies from outside the United States have also uncovered a possible temperature-related trend in headache occurrences. In both the Taipei and Seoul studies—published in 2015 and 2018, respectively—the incidence of migraines associated with particulate matter was higher on hotter days.

One specific pollutant—sulfur dioxide—was only associated with increased headache visits on warmer-temperature days (73 degrees or higher) in the Taipei study. For comparison, researchers in the Seoul study concluded that sulfur dioxide did not have as significant an association with headaches as other pollutants.

Researchers also considered the role of ground-level ozone, which is more likely to reach unhealthy levels on hot sunny days. Howarth explained that ozone is a secondary pollutant, meaning it is formed in the air only when there is sunlight, volatile organic chemicals, and nitrogen oxides.

Ozone is considered “good” when it occurs naturally in the upper atmosphere—away from where humans breathe—but the gas also can be created at ground level when industrial pollutants react with sunlight.Exposure to ozone may cause headaches and exacerbate seasonal allergies, Howarth said.

Can Hot Weather Give You a Heat Headache?

Check the AQI Before You Go Outside

You can check the air quality index (AQI) wherever you get your weather report to gauge your possible exposure to pollutants on a given day and location. AQI values span from 0 to 500, with higher numbers representing higher levels of pollution. Values at or below 100 are considered safe or satisfactory.

Pace told Verywell that people may begin to notice symptoms related to poor air quality once the AQI is around 150. Those who are more sensitive to air quality may notice symptoms at slightly lower AQIs, she said.

Sensitive or at-risk groups may include:

People who are sensitive to air pollution should consider making outdoor activities shorter and less intense when the AQI inches toward 100 and above. If the AQI is greater than 100, sensitive groups should keep medicine handy in case of symptoms.

When the AQI reaches a level that’s considered unhealthy for everyone—150 and up—more people are likely to experience adverse health effects. It’s important to heed weather alerts about unhealthy air quality, no matter your health history. On bad AQI days, avoid long or intense outdoor activities and consider moving activities indoors.

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What This Means For YouIf you are outside in an area with poor air quality and you feel a headache coming on, that’s your sign to head indoors and take necessary measures to alleviate the pain.

What This Means For You

If you are outside in an area with poor air quality and you feel a headache coming on, that’s your sign to head indoors and take necessary measures to alleviate the pain.

12 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Penn Medicine.Why climate change might be affecting your headaches.Elser H, Rowland ST, Marek MS, et al.Wildfire smoke exposure and emergency department visits for headache: a case-crossover analysis in California, 2006-2020.Headache. 2023;63(1):94-103. doi:10.1111/head.14442Environmental Protection Agency.Why wildfire smoke is a health concern.National Institute for Occupational Safety and Health.Benzene.National Institute for Occupational Safety and Health.Toluene.Lee H, Myung W, Cheong HK, et al.Ambient air pollution exposure and risk of migraine: synergistic effect with high temperature.Environ Int. 2018;121(Pt 1):383-391. doi:10.1016/j.envint.2018.09.022Chiu HF, Weng YH, Chiu YW, Yang CY.Air pollution and daily clinic visits for headache in a subtropical city: Taipei, Taiwan.Int J Environ Res Public Health. 2015;12(2):2277-2288. doi:10.3390/ijerph120202277American Lung Association.Ozone.Centers for Disease Control and Prevention.Ozone.Environmental Protection Agency.Air data basic information.Environmental Protection Agency.Patient exposure and the air quality index.New York State Department of Health.Exposure to smoke from fires.

12 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Penn Medicine.Why climate change might be affecting your headaches.Elser H, Rowland ST, Marek MS, et al.Wildfire smoke exposure and emergency department visits for headache: a case-crossover analysis in California, 2006-2020.Headache. 2023;63(1):94-103. doi:10.1111/head.14442Environmental Protection Agency.Why wildfire smoke is a health concern.National Institute for Occupational Safety and Health.Benzene.National Institute for Occupational Safety and Health.Toluene.Lee H, Myung W, Cheong HK, et al.Ambient air pollution exposure and risk of migraine: synergistic effect with high temperature.Environ Int. 2018;121(Pt 1):383-391. doi:10.1016/j.envint.2018.09.022Chiu HF, Weng YH, Chiu YW, Yang CY.Air pollution and daily clinic visits for headache in a subtropical city: Taipei, Taiwan.Int J Environ Res Public Health. 2015;12(2):2277-2288. doi:10.3390/ijerph120202277American Lung Association.Ozone.Centers for Disease Control and Prevention.Ozone.Environmental Protection Agency.Air data basic information.Environmental Protection Agency.Patient exposure and the air quality index.New York State Department of Health.Exposure to smoke from fires.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Penn Medicine.Why climate change might be affecting your headaches.Elser H, Rowland ST, Marek MS, et al.Wildfire smoke exposure and emergency department visits for headache: a case-crossover analysis in California, 2006-2020.Headache. 2023;63(1):94-103. doi:10.1111/head.14442Environmental Protection Agency.Why wildfire smoke is a health concern.National Institute for Occupational Safety and Health.Benzene.National Institute for Occupational Safety and Health.Toluene.Lee H, Myung W, Cheong HK, et al.Ambient air pollution exposure and risk of migraine: synergistic effect with high temperature.Environ Int. 2018;121(Pt 1):383-391. doi:10.1016/j.envint.2018.09.022Chiu HF, Weng YH, Chiu YW, Yang CY.Air pollution and daily clinic visits for headache in a subtropical city: Taipei, Taiwan.Int J Environ Res Public Health. 2015;12(2):2277-2288. doi:10.3390/ijerph120202277American Lung Association.Ozone.Centers for Disease Control and Prevention.Ozone.Environmental Protection Agency.Air data basic information.Environmental Protection Agency.Patient exposure and the air quality index.New York State Department of Health.Exposure to smoke from fires.

Penn Medicine.Why climate change might be affecting your headaches.

Elser H, Rowland ST, Marek MS, et al.Wildfire smoke exposure and emergency department visits for headache: a case-crossover analysis in California, 2006-2020.Headache. 2023;63(1):94-103. doi:10.1111/head.14442

Environmental Protection Agency.Why wildfire smoke is a health concern.

National Institute for Occupational Safety and Health.Benzene.

National Institute for Occupational Safety and Health.Toluene.

Lee H, Myung W, Cheong HK, et al.Ambient air pollution exposure and risk of migraine: synergistic effect with high temperature.Environ Int. 2018;121(Pt 1):383-391. doi:10.1016/j.envint.2018.09.022

Chiu HF, Weng YH, Chiu YW, Yang CY.Air pollution and daily clinic visits for headache in a subtropical city: Taipei, Taiwan.Int J Environ Res Public Health. 2015;12(2):2277-2288. doi:10.3390/ijerph120202277

American Lung Association.Ozone.

Centers for Disease Control and Prevention.Ozone.

Environmental Protection Agency.Air data basic information.

Environmental Protection Agency.Patient exposure and the air quality index.

New York State Department of Health.Exposure to smoke from fires.

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