Warm Weather May Trigger Migraines
Temperature Increase Is the Biggest Weather-Related Headache Trigger, Research Suggests
WebMD News Archive
March 9, 2009 -- Most migraine sufferers believe that weather changes can
bring on their headaches, but the scientific proof has been lacking -- until
New research suggests that certain weather conditions may trigger migraines
and other severe headaches. But frequent sufferers may be surprised by some of
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
“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
“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.
Other Headache Triggers
Migraine specialist Stephen Silberstein, MD, a spokesman for the American
Academy of Neurology, tells WebMD that patients often can reduce the number and
severity of the headaches they have by understanding their own triggers.
Common migraine triggers include:
- Hormonal changes. For many women, migraines are closely linked to their
menstrual cycle, with headaches occurring immediately before or during their
- Diet and eating habits. Fasting or skipping meals and dehydration are two
big migraine triggers, Silberstein says.
- Overuse of pain drugs for headaches. This can lead to rebound
- Intense exertion. Strenuous exercise and even sex can bring on
- Changes in sleep habits and stress. Getting too much or too little sleep
can trigger headaches. And stress is a big trigger for many people.
Many migraine sufferers believe that particular foods trigger their
headaches. Silberstein says it is clear that alcohol, the flavor enhancer MSG,
and caffeine withdrawal can do this.
But he adds that there is little scientific evidence linking other commonly
cited foods like chocolate and artificial sweeteners to headaches.