Migraines & Headaches Resource Center

It seems like there are a million reasons that people get migraines. There used to be only a few. Of course, there used to be all kinds of ideas as to what these debilitating headaches are, and finally doctors decided they are migraines, and decided they are also real – not something that’s just “in your head.”

So, there are now more ideas as to what causes migraines. The newest culprits that researchers feel trigger migraines might be high temperatures and low air pressure, according to a large study published online today in the Journal of Neurology. But researchers did not find a clear association between headaches and air pollution.

Weather — especially changes in air pressure — is frequently cited as a headache trigger but it had not previously been shown in such a large, well-designed study.

The researchers, from Boston’s Beth Israel Deaconess Medical Center and the Harvard School of Public Health, looked into the idea of pollution as a trigger because fine particulate pollutants cause or complicate other health problems, including heart attacks, stroke, congestive heart failure and asthma.

There were over 7,000 headache patients of both genders and varying ages and ethnic groups in the migraine study, who were seen at the medical center’s emergency room between May 2000 and December 2007. Researchers looked at temperature levels, barometric pressure, humidity, fine particulate matter and other pollutants during the three days before each patient was seen in the ER and for a control day, in which the patient did not report a headache.

Headaches were strongly associated with rising temperatures. An increase of 5 degrees Celsius (9 degrees F, as a reader has so kindly pointed out below) increased the risk of migraine by 7.4%. Low air pressure, which often precedes storms, played a smaller role.

“This study points to the fact that changes in temperature are migraine triggers, and that’s something that’s not been known before,” said Dr. Richard Lipton of the Montefiore Headache Center in New York City.

Knowing what can trigger an attack gives migraine sufferers a measure of control, said Lipton, who was not associated with the study. One of his patients, for example, moved from New York City to Arizona because air pressure in the Southwest is less changeable.

Triggers often work together, so migraines can be brought on by a combination of them. Perhaps red wine or chocolate is a trigger for some people. If there are some weather issues and a migraine sufferer has some chocolate or red wine during a temperature change, the results could be more debilitating than usual. More studies are ongoing to look more closely at the weather as a trigger.