A stroke is a medical condition that occurs when the blood and oxygen supply to the brain decrease or are cut off. Three types of strokes exist: ischaemic stroke, caused by a clot in a blood vessel in your brain; haemorrhagic stroke, which occurs when an artery in the brain breaks open; and transient ischemic attack (TIA), which is caused by a small clot that briefly blocks an artery. While age, family history, and pre-existing conditions can increase the risk of stroke, cold temperatures can also make one prone to the condition, said Dr Kunal Bahrani, Director of Neurology, Fortis Escorts Hospital, Faridabad, adding that it could be due to several factors.
Why Stroke Risk Increases During Winter?
In a 2016 study published in the Journal of Stroke and Cerebrovascular Diseases, researchers found that higher temperatures were associated with lower occurrences of stroke hospitalisation, whereas lower average temperatures and larger temperature fluctuations posed a greater risk of stroke hospitalisation among the study participants.
Another study published in the European Journal of Epidemiology observed that for every 2.9 °C temperature decrease over 24 hours, stroke risk increased by 11%. The same study found that people with a higher cardiovascular risk had a 30% increased risk of stroke.
According to Dr Bahrani, the risk of a winter stroke increases due to a combination of factors.
He explained, “Cold weather can lead to increased blood pressure as blood vessels constrict to conserve heat. This elevation in blood pressure, coupled with the higher viscosity of the blood in colder temperatures, raises the risk of clot formation.”
“Moreover, during winter, people tend to be less active, leading to weight gain and an increased likelihood of developing conditions like diabetes and high cholesterol, both of which are significant risk factors for strokes,” he added.
Other factors that may contribute to the burden include respiratory infections, which are likely to trigger inflammation, impacting blood vessel function.
Who Is More At Risk?
Certain individuals are more prone to winter strokes. The elderly, already at risk due to age-related vascular changes, face heightened susceptibility. Those with pre-existing conditions like hypertension or cardiovascular diseases also have an increased risk. Lifestyle choices, such as smoking and a poor diet, further contribute to vulnerability.
According to the World Health Organization (WHO) Eastern Mediterranean Region, 1.5 crore people worldwide suffer from a stroke each year, of which 50 lakh people die and another 50 lakh are left permanently disabled.
Given the prevalence of the condition, it is extremely important to assess your risk and take proper measures against it.
High blood pressure, smoking, diabetes, an unhealthy diet, physical inactivity, high cholesterol, and obesity are some of the most common risk factors for stroke, which are modifiable, according to the American Heart Association (AHA). Other non-modifiable risk factors include age, family history, race, gender, and prior stroke, TIA, or heart attack.
Also Read: Why Do Women Have A Higher Risk Of Stroke Than Men
Tips To Reduce Stroke Risk In Winter
Some of the ways you can reduce your risk of stroke in the winter include:
- Staying warm is important as cold temperatures can constrict blood vessels, raising the risk of blood clots. Layer up to maintain body heat.
- Drinking plenty of fluids to prevent the thickening of the blood
- Maintaining regular physical activity to promote blood circulation and keep the cardiovascular system healthy
- Eating a well-balanced diet, which includes fruits, vegetables, and omega-3 fatty acids
Lastly, Dr Bahrani advised seeking medical advice if you develop symptoms, including warning numbness, difficulty speaking, or sudden headaches.