Factors causing stroke in cold season

Low temperatures cause sudden high blood pressure, increased blood concentration, reduced oxygen to the brain, increasing the risk of stroke.

Dr. Vu Van Nam, Department of Neurology - Stroke, Tam Anh General Hospital, Hanoi, said that strokes tend to increase in cold weather , especially in the elderly and people with underlying diseases. Strokes often occur at midnight and early morning because the temperature is lower than at other times.

Doctor Nam points out some reasons why cold weather increases the risk of stroke below.

Vasoconstriction and sudden increase in blood pressure: When the temperature is low, the body reacts by constricting peripheral blood vessels (blood vessels that carry blood from the heart to organs far from the heart) to keep warm, concentrating blood on important organs, leading to increased blood pressure, putting great pressure on the circulatory system. High blood pressure also puts pressure on blood vessels, causing rupture - the leading risk factor for hemorrhagic stroke. Cold weather also stimulates the sympathetic nervous system, increasing the secretion of hormones such as adrenaline, causing vasoconstriction, increasing heart rate, and placing a burden on the cardiovascular system, especially in people with a history of heart disease or high blood pressure.

Increased blood viscosity: In cold weather, blood becomes thicker and more viscous to retain body heat, increasing the risk of blood clots forming in blood vessels. Blood clots block blood flow to the brain, leading to ischemic stroke.

Increased heart rate: When the weather turns cold, the body needs to produce more heat to keep warm, causing the heart rate to increase to pump blood faster to maintain body temperature. High heart rate increases the burden on the heart, easily leading to arrhythmia or other cardiovascular events related to stroke. For people with cardiovascular disease, the heart working too hard for a long time can easily cause a heart attack or stroke.

Hanoians in the cold of January 2024. (Illustration: Giang Huy).

Reduced oxygen to the brain: Dry air from cold weather reduces the efficiency of oxygen exchange in the lungs. When the brain does not receive enough oxygen, the risk of stroke increases. People with chronic lung or cardiovascular disease are at higher risk.

Unhealthy habits: In winter, the weather is often late in the morning and early in the evening, which can easily lead to circadian rhythm disorders due to lack of sunlight. People tend to reduce physical activity, change sleep patterns, affecting blood pressure and metabolism, indirectly increasing the risk of stroke. Dr. Nam said that eating a lot of foods rich in fat and salt can easily increase blood pressure and obesity - two major risk factors for stroke.

Stroke is an acute disease that occurs suddenly, with a high mortality rate and disability complications. To reduce the risk of stroke in the cold season, Dr. Nam recommends that everyone keep their body warm, especially the head and neck area, wear enough warm clothes, wear scarves and gloves when going out. Monitor blood pressure regularly, especially the elderly or those with a history of blood pressure, diabetes, and high blood fat.

Eat scientifically (limit alcohol, greasy foods, fast food.), increase indoor exercise for about 30 minutes a day. Drink enough water even if you don't feel thirsty because the body needs enough water to maintain good blood circulation. Stroke screening in the cold season helps protect health and proactively prevent it.

Patients with symptoms such as weakness in limbs, numbness in limbs, difficulty speaking, crooked mouth, sudden dizziness, need to quickly go to the nearest medical facility for stroke treatment for timely diagnosis and treatment. The "golden" time for stroke emergency is before 4.5 hours from the time of symptom onset. Patients who receive emergency treatment early have high treatment effectiveness.