04/01/2026
& Risk of
1. Why Increase in
Cold exposure triggers several physiological changes:
• Vasoconstriction: Blood vessels become narrow to conserve heat → increases blood pressure.
• Increased cardiac workload: The heart must pump harder against tighter vessels.
• Higher oxygen demand: The heart muscle needs more oxygen when working harder.
• Increased blood thickness: Cold causes blood to become more viscous → increases risk of clot formation.
• Sympathetic activation: Cold stress triggers release of adrenaline → increases heart rate and can precipitate plaque rupture.
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2. Who Is Most at Risk?
• People with existing coronary artery disease
• Elderly individuals
• Patients with hypertension, diabetes, or high cholesterol
• Smokers
• Those engaging in strenuous activity in the cold (e.g., shovelling snow)
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3. Common Triggers in Winter
• Sudden exposure to very cold air
• Early morning activity (when temperature and blood pressure both peak)
• Heavy exertion in cold
• Poorly controlled BP during winter
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4. How to Reduce the Risk
• Keep warm: layers, gloves, covering face/nose
• Avoid sudden heavy exertion in cold
• Warm up indoors before going out
• Manage BP, sugar, cholesterol well
• Regular medications and check-ups
• Avoid smoking and secondhand smoke
• Stay hydrated (cold reduces thirst)
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5. Symptoms to Watch For
• Chest pain/pressure
• Shortness of breath
• Pain radiating to arm, jaw, or back
• Nausea, sweating, dizziness