Cardiologist explains why more heart attacks happen in winter

Cold weather increases heart attack risks due to vessel constriction, thickened blood, and winter habits. Learn expert-backed tips to protect your heart. (Image: Pexels)

The winter months are temperate and many people associate them with joy, escape and outdoor activities. But lurking behind the season of good will is an underlying risk for heart health. Indeed, cardiologists the world over note a dramatic increase in heart attack occurrence during colder months, particularly in those with pre-existing heart disease, hypertension, diabetes and high cholesterol. Even seemingly healthy individuals can find themselves suddenly having cardiac problems in the winter.

Cold temperatures make the heart work harder to keep the body warm. This leads to constricted blood vessels, higher blood pressure and added strain on the heart. Meanwhile, winter lifestyle factors — less physical activity, heavier food and more drinking or smoking – can quietly damage the cardiovascular system. Seasonal infections like the flu also cause inflammation that can destabilize arteries and lead to heart attacks.

But because the changes happen slowly and aren't always immediately obvious, most people don't grasp how dangerous they can be.

“If one knows how winter seasons affect the heart and take necessary precautions in advance, this can augment to mulch down unprecedented emergencies” says Dr P L N Kapardhi-Clinical Director, Cath Lab & Sr. Interventional Cardiologist, CARE Hospitals- Banjara Hills-Hyderabad

Also Read: Heart attacks without chest pain: Why atypical symptoms are dangerous

However, with awareness and healthy lifestyle modifications (and advice from a medical professional), we can enjoy winter safely and in ways that won't harm our heart.

1. Cold weather strains the heart

As the cold sets in, the blood vessels shrink to hold on to warmth. When that happens, blood pressure inches up and the heart has to push harder than usual, even at rest. For someone who already has borderline blood pressure, diabetes, high cholesterol, or quiet blockages they may not even be aware of, this added strain can be enough to upset the balance.

2. Thickened blood increases clot risk

Cold conditions can make the blood comparatively thicker and stickier. This raises the chances of clot formation — which is the root cause of most heart attacks. Even mild dehydration in winter (which is more common than we think) can make the blood more concentrated, further raising the clotting tendency.

3. Sudden temperature changes can trigger events

Going from a warm room to cold air outside — or taking an early-morning walk without proper layering — creates abrupt stress on the cardiovascular system. For some people, this sudden change can set off chest discomfort, irregular heartbeats, or in severe situations, even a heart attack.

4. Winter infections add hidden pressure

Seasonal infections like flu, viral fevers and respiratory illnesses are more frequent in winter. These illnesses increase inflammation in the body and can raise heart rate and oxygen demand. For people with compromised heart function, this combination becomes a dangerous mix.

5. Reduced physical activity and heavier meals

Cold weather usually slows daily habits — exercise drops, mornings stretch out, and heavier comfort foods start to take over. When activity dips, metabolism slows and cholesterol tends to climb. Add in heavy or festive meals, and you can see sharp jumps in blood pressure and sugar levels, both of which can set off heart trouble.

6. Early-morning exertion is riskier

Many heart attack cases in winter occur in the early hours. The body’s natural stress hormones peak at this time, and combined with cold temperatures, they increase the heart’s workload. Older adults and those with known heart disease should avoid high-intensity activity first thing in the morning.

Also Read: Cardiologists flag outdated symptoms of heart attack and stroke, say even the ‘healthy’ are at risk

A cardiologist’s advice

FAQs on Increased Heart Attacks in Winter:

As the cold sets in, the blood vessels shrink to hold on to warmth. This raises blood pressure and forces the heart to work harder than usual, even at rest. For someone with borderline blood pressure, diabetes, high cholesterol, or quiet blockages, this added strain can upset the balance.

2. How does thicker blood increase clot risk?

Cold conditions can make the blood thicker and stickier, raising the chances of clot formation—the root cause of most heart attacks. Even mild dehydration in winter can make the blood more concentrated, further increasing clotting tendencies.

3. Can sudden temperature changes trigger heart events?

Going from a warm room to cold air outside or taking an early-morning walk without proper layering creates abrupt stress on the cardiovascular system. For some people, this sudden change can cause chest discomfort, irregular heartbeats, or severe situations like a heart attack.

4. How do winter infections add hidden pressure?

Seasonal infections like flu, viral fevers, and respiratory illnesses increase inflammation in the body and can raise heart rate and oxygen demand. For people with compromised heart function, this becomes a dangerous mix.

5. Do reduced physical activity and heavier meals affect heart health?

Cold weather slows daily habits—exercise drops, mornings stretch out, and heavier comfort foods take over. When activity dips, metabolism slows, and cholesterol climbs. Heavy or festive meals can cause sharp jumps in blood pressure and sugar levels, potentially leading to heart trouble.

Disclaimer: This article, including health and fitness advice, only provides generic information. Don’t treat it as a substitute for qualified medical opinion. Always consult a specialist for specific health diagnosis.