Cold weather and high humidity increase the chance of stroke and can prove to be so fatal that people might have to be hospitalised, says a new study.
Study leader Judith Lichtman, 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 hospitalisations."
The study also revealed that the risk of a stroke reduced by 3 per cent for every 5 degrees rise in temperature.
Experts say blood pressure rises and vessels contract in cold conditions. They say blood becomes stickier and its tendency to clot rises in extreme conditions because in such weather heart is forced to work more.
Every year, about 800,000 Americans suffer from stroke and in most of the cases, clots block a blood vessel to the brain with high blood pressure causing a major risk factor.
Larry Goldstein, a Duke stroke specialist who worked on the study, said, "High humidity may cause dehydration and this can raise the risk for clots." Doctors say one should stay in heater during cold to minimise the risk of any hospitalisation due to stroke.
The research team analysed a sample of 1,34,510 people, who were 18 years and older and were hospitalised in 2009-10 for ischemic stroke. This is the most common type of stroke caused due to blood clot.