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As the temperatures decrease, the likelihood of having a stroke increases, which has been noted by medical professionals and researchers worldwide. Numerous investigations, including those shared in The Lancet and Stroke, have indicated a significant rise in ischemic stroke incidents during the colder months, particularly when average temperatures drop below 13 degrees Celsius. Dr. Manoj Khanal, who is the Director of Neurosciences at Max Super Speciality Hospital in Shalimar Bagh, mentions that cold weather influences the heart and blood circulation in various ways, such as elevating blood pressure, thickening the blood, and even heightening the chances of clot formation. He notes, "When you compare cold temperatures to warmer ones, there are many more patients dealing with high blood pressure and large artery atherosclerotic strokes in the lower temperature group."
As World Stroke Day 2025 emphasizes the importance of prevention, specialists are calling for increased awareness regarding how seasonal shifts can impact brain health. Grasping this relationship is especially important in northern India, where winter temperatures can drop drastically, leading to bodily stress responses that amplify the risk of both ischemic and hemorrhagic strokes.
How Cold Weather Elevates Stroke Risk:
Blood Pressure Goes Up As Blood Vessels Tighten: "In cold weather, blood vessels tighten to preserve body warmth, which raises blood pressure and puts added pressure on the heart system," Dr. Khanal explains. The World Health Organization (WHO) states that high blood pressure is the main adjustable risk factor for strokes, and there tend to be more uncontrolled cases during the winter months.
Thicker Blood And Increased Clotting Risk: "Low temperatures can cause blood to thicken a bit, making it more likely to clot," Dr. Khanal explains. These clots can block the blood flow to the brain, leading to an ischemic stroke. A 2023 article in the Journal of the American Heart Association (JAHA) showed that cooler temperatures are associated with higher blood thickness and increased platelet activity, which raise the chances of clot formation.
Less Physical Activity And Weight Gain: In the winter, people usually move around less and eat more foods that are high in calories. Dr. Khanal says, "Less exercise leads to weight gain, higher cholesterol levels, and increased blood pressure—all factors that heighten stroke risk." The American Stroke Association points out that even moderate activity, like brisk walking for half an hour each day, can lower stroke risk by as much as 25%.
Less Hydration In Cold Weather: "In winter, many individuals feel less thirsty, which can result in dehydration," Dr. Khanal notes. "This makes the blood thicker and more susceptible to clotting." A study from the European Journal of Preventive Cardiology in 2021 found that dehydration increases blood concentration and platelet clumping, which are two major factors contributing to stroke development.
Overexertion In Cold Weather: Doing hard work in chilly weather, like shoveling snow or working outside, can significantly increase your heart rate and blood pressure. "Any quick physical effort in cold conditions can put strain on the heart and increase the risk of a stroke," warns Dr Khanal. The National Institute of Neurological Disorders and Stroke (NINDS) states that such activities can cause strokes in people who already have heart or artery issues.
Seasonal Infections and Inflammation: "The winter season also brings the flu and other respiratory infections," Dr Khanal notes. "Swelling from these infections can harm blood vessels and make high blood pressure and heart problems worse, raising the likelihood of a stroke." A study published in the Neurology journal in 2022 shows that respiratory infections can lead to a three times higher chance of having a stroke within the first three days of getting sick.
How To Lower Stroke Risk In Cold Weather?
"Being careful in winter is very important," Dr Khanal stresses. He suggests the following actions:
Stay Warm: "Wear multiple layers to keep your body warm and avoid narrowing of blood vessels."
Stay Active: Do some light exercises indoors; do not push yourself too hard.
Stay Hydrated: Make sure to drink enough fluids, even if you do not feel thirsty.
Manage Co-Morbidities: Keep your blood pressure, cholesterol, and diabetes in check.
Limit Alcohol And Avoid Smoking: "While alcohol can temporarily widen blood vessels, it can put extra strain on your heart; smoking tightens blood vessels and raises blood pressure."
Get Flu Vaccinated: "Getting the flu shot helps to prevent respiratory infections and, in turn, lowers the chance of a stroke by reducing blood vessel swelling." A 2024 study from BMJ showed that flu vaccination was linked to a 12% lower stroke risk in adults over the age of 50.
Both very hot and very cold temperatures can increase stroke risk, but harsh cold has longer-lasting effects, according to various studies. Cold weather is linked not only to ischemic strokes but also to high blood pressure, bleeding events, and blood vessel inflammation.
If you suddenly feel symptoms like imbalance, weakness in your face, numbness in your arms or legs, or difficulty speaking in cold weather, hurry to the closest hospital that is equipped to handle strokes for immediate medical help. Quick treatment is essential for recovery.
