Why Heart Attacks Are More Common in the Winter, According to a Cardiologist

Heart attack rates increase in the winter—a cardiologist explains why.

The winter might bring about the happiness of the holidays and hot chocolate galore, but the season also comes with a scary statistic: increased heart attacks. For a 2018 study published in JAMA Cardiology, researchers looked at weather data points corresponding with hundreds of thousands of heart attacks in Sweden; they concluded that days with below-freezing temperatures had the highest heart attack rates. So, why are heart attacks more common in winter?

It's because of what the weather does to your body internally that ultimately makes a difference. "Heart attacks are more common in winter because … cold temperatures can constrict heart vessels," explains Sanjiv Patel, MD, a cardiologist at MemorialCare Heart & Vascular Institute in Fountain Valley, California. When your heart vessels constrict, there's reduced blood flow to the organ, which increases the risk of a heart attack.

But it's not just heart vessels: Cold weather causes all blood vessels to tighten in order to preserve core body temperature. That forces your blood pressure to rise, putting even more strain on your heart.

Another reason why heart attacks are more common in the winter is because of the rise in upper respiratory infections. As Patel explains, these illnesses "lead to more inflammation in the body, which then can destabilize existing buildup in the arteries or make the buildup worse."

The last thing you probably want to think about during what should be the most cheerful time of year is a heart attack, but it's important to consider these added risk factors as the temperature dips. After all, sadly, the day you're at the highest risk for a heart attack, according to a 2018 BMJ study, is Christmas Eve. And for the heart attack symptoms to be aware of, These Are the Heart Attack Warning Signs Hiding in Plain Sight.

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