Weather Changes as Migraine Triggers
Migraine sufferers have always reported that the weather affects their headaches. Even the Greeks talked about "hot winds and cold winds". Exactly how the weather affected headaches was not clear until formally studied. Canadian researchers looked at the effects of the chinook winds on migraines, and found a correlation. They reported that the most favorable "headache weather" was warm, dry, and with higher barometric pressure. You know, like a nice summer day.
Since then, several other studies have looked at weather and migraine but the results have been a little bit confusing. This may be partly because the early studies were small, and did not have very many people in them. It may also be partly because not all migraine sufferers are alike. And another study concludes that formal weather modelling may yield better information than patients' observations.
A 2004 study conducted at the New England Center for Headache followed 77 migraine patients who kept headache diaries for 2 to 24 months. The headache diary data were compared to National Weather Service data. The most interesting thing about this study was that although 63% of migraine sufferers thought they were affected by the weather, only 51% of them were actually affected by the weather factors they thought influenced their migraines.
The weather factors most likely to influence migraines were temperature and humidity, high or low. The second most likely factor was any significant change in the weather, which affected 14% of migraine sufferers, and barometric pressure changes, again high or low, which affected 13%. Interestingly, 39% were sensitive to one weather factor, and 12% to two. So, in this study, no single weather change affected everyone the same way.
A 2009 study of weather conditions preceding emergency department visits for migraine found that the biggest trigger was higher ambient temperature, but that low barometric pressure was also a trigger. This was a large study, with over 7000 patients seen over a 7-year span.
Additional studies confirm the connection between both hot weather and drops in barometric pressure as triggers.
There isn't much you can do to avoid the weather, but as our understanding of the biological effects of climate changes grows, you can at least predict these triggers a little better.
Useful Resource: http://www.mediclim.com/