Why stroke risk increases in the colder months? Neurosurgeon explains how winter affects the blood flow in the brain

While winter brings with it foggy mornings, festivals and comfort, With the lowering of temperature and the onset of winter, several physiological changes occur in the human body-some subtle, others potentially dangerous. Understanding how winters affect brain blood flow, help people stay protected and safe.These weather changes go a long way toward explaining why stroke rates regularly increase during winter months throughout many parts of the world.Magnesium and dementia risk: What happens to your brain when you take magnesium daily During exposure to low temperatures, blood vessels naturally constrict in a process known as vasoconstriction; this helps to conserve body heat. At the same time, this raises blood pressure because the heart then has to work harder in moving the blood through narrowed vessels. High blood pressure is already known to be one of the major risks for both ischemic stroke, wherein the arteries become blocked, and haemorrhagic stroke, wherein a burst of blood vessels occurs.Cold temperatures might act to thicken the blood, making circulation in general, and to the brain in particular, slower. With thicker blood, the possibility of clot formation is enhanced, further reducing oxygen delivery to brain tissues. If an individual is already vulnerable to cardiovascular problems, such a combination of reduced flow and increased risk of clotting can seriously heighten their chances of experiencing a stroke.Most of the strokes occur in early morning, when the temperature is the lowest, causing sudden spikes in blood vessels and cerebral arteries.Lifestyle changes during winter also contribute to these risks. People are less active, spend more time indoors, and gain weight or have different diets. Also, respiratory infections, such as flu, are more common in the cold months and can cause inflammation, which increases clotting risks.For those already suffering from conditions such as hypertension, diabetes, and high cholesterol, these physiological changes during winter will only extend an already stressed circulatory system to its limits.Cold weather can trigger cardiac conditions like atrial fibrillation which can dislodge clots to the brainAlthough the impact on brain blood flow is unavoidable during winter, some modalities help reduce stroke risk by regularly staying physically active, heart-healthy eating, managing chronic conditions by taking prescribed medicines regularly , staying warm outdoors, staying hydrated and seeking vaccination for seasonal illnesses.Remember the FAST rule:• Face drooping• Arm weakness• Speech difficulty• Time to rush to the hospitalAwareness and prevention will remain the key, especially among those with higher risks. Understanding how winter affects the brain and circulation enables the individual to take some precautionary steps so that the colder season remains safe and healthy.Dr. Gaurav Batra, Neurosurgeon (Brain & Spine), Max Super speciality Hospital, Vaishali