Sudden change in weather could trigger stroke

A sudden change in weather temperature may increase one's risk of stroke, especially when it gets colder, according to a recent study.

Researchers found that people are more likely to suffer a stroke and die when there are sudden changes in air temperature and higher humidity.

On the other hand, warmer weather lowers the risk of needing treatment at healthcare facilities for a stroke and even improves one's chances of survival, they found. The risk of stroke during cooler weather is higher because direct exposure to cold increases blood pressure and constriction of blood vessels.

Judith Lichtman, lead study author and associate professor in epidemiology at the Yale School of Public Health, said: "Weather is not something people would typically associate with stroke risk, however, we've found weather conditions are among the multiple factors that are associated with stroke hospitalizations."

Lichtman and her team identified a nationwide sample of 134,510 people, aged 18 and older, who were admitted to the hospital in 2009 and 2010 for ischemic stroke. They compared this information to data on the weather, including temperature and dew points.

The results showed that larger daily temperature changes and higher average humidity were associated with higher stroke hospitalization rates.

"The study suggests that meteorological factors such as daily fluctuations in temperature and increased humidity may be stressors that increase stroke hospitalizations," Lichtman said. "People at risk for stroke may want to avoid being exposed to significant temperature changes and high dew point and, as always, be prepared to act quickly if they or someone they know experience stroke signs and symptoms."

The researcher stressed that further research is still necessary to better understand the cause and effect of changes in weather condition on stroke risk as well as to further explore the mechanisms for this association.