Warm Weather May Trigger Migraines
Temperature Increase Is the Biggest Weather-Related Headache Trigger, Research Suggests
March 9, 2009 -- Most migraine sufferers believe that weather changes can bring on their headaches, but the scientific proof has been lacking -- until now.
New research suggests that certain weather conditions may trigger migraines and other severe headaches. But frequent sufferers may be surprised by some of the findings.
The study reveals that:
- Regardless of the time of year, an increase in temperature was the biggest weather-related headache trigger. Researchers reported that every 9 degree Fahrenheit increase in temperature raised the headache risk by 7.5%.
- Low barometric air pressure is considered by some to be specific to migraines, but the study found no link between migraines and low-pressure systems. The researchers say lower pressure was associated with a small increase in risk for non-migraine headaches.
- Air pollution was not strongly associated with an increased risk for migraine or non-migraine headaches. But the automobile exhaust pollutant nitrogen dioxide did show a borderline effect on non-migraine headaches.
Weather, Pollution, and Migraines
The study is one of the largest ever to examine the impact of weather and air pollution on headaches.
But study lead author Kenneth J. Mukamal, MD, of Boston’s Beth Israel Deaconess Medical Center and Harvard School of Public Health, tells WebMD that an even bigger study would be needed to understand the impact of air pollution on headaches.
“We are not saying that air pollution is not a headache trigger,” he says. “What we can say with some confidence is that the effect is not enormous.”
Mukamal and colleagues compared the medical records of 7,054 headache patients treated at a Boston hospital’s emergency department over a seven-year period to official records of pollution levels and weather conditions in the days before treatment.
Specific weather conditions including temperature, barometric pressure, and humidity were also examined at other key time periods.
Although rising temperature was identified as the biggest weather-related headache trigger, the researchers concluded that the impact may not be clinically meaningful.
“This magnitude of excess risk is obviously modest and may not be an important factor in the clinical management of individual patients, given the many other potential triggers of migraine that patients face,” they write.
The study was published in the journal Neurology and was supported by the National Institute of Environmental Health and Sciences and the Environmental Protection Agency.