If you suffer from migraines, you might track your sleep, stress and diet, but new research suggests you should also keep a close eye on the smog report.

Air pollution — from car exhaust to industrial smoke — is a significant driver of migraine activity, especially when combined with specific weather patterns, according to findings published April 15 in Neurology.

For the study, researchers followed 7,032 people in southern Israel over an average 10 years.

They also tracked daily levels of airborne pollutants like nitrogen dioxide (NO₂) and particulate matter (PM2.5), which come from traffic and power plants, as well as weather conditions. 

They then compared that information to visits to a hospital or doctor's office for acute migraine. The comparison also looked at the seven days before the visit and at pharmacy records to see how many doses of migraine medications, called triptans, people needed.

Researchers found that on days when air quality dipped, hospital visits for acute migraines spiked.

Specifically:

• People exposed to sudden spikes of NO₂ were 41% more likely to seek emergency care for a migraine. 

• High levels of solar radiation and UV rays increased the risk of visits by 23%.

• The fewest medical visits occurred on days with lower-than-average pollution levels.

• People with ongoing exposure to high levels of NO₂ were 10% more likely to have high use of migraine drugs than people without. 

• People with ongoing exposure to high levels of PM2.5 were 9% more likely to have high use of the drugs.

Study leader Dr. Ido Peles of Ben-Gurion University of the Negev in Israel said the results shed light on how and when migraine attacks occur.

“They suggest that for people who have a susceptibility to migraine to begin with, environmental factors may play two roles," he said.

"Intermediate-term factors such as heat and humidity may modify the risk for attacks, while short-term factors such as spikes in pollution levels may trigger attacks.”

The study also noted a strange synergy between weather and smog. 

High temperatures and dry air made the effects of traffic pollution worse. Conversely, cold and damp conditions intensified the impact of fine soot particles (PM2.5). This suggests that climate change, which increases the frequency of heat waves and dust storms, could trigger a migraine surge in polluted areas.

“As climate change intensifies the frequency of heat waves, dust storms and pollution episodes, we will need to integrate these environmental risk factors into our guidance for people with migraine,” Peles explained.

While the study does not definitively prove that pollution causes the attacks, it showed a consistent link, researchers said. 

They note that further study is needed using other measures for migraine activity in the wake of pollution.