Cold “Heart” Facts – Winter Can Increase Cardiovascular Disease Risk

For some, winter is the most joyous time of the year, filled with family, festivities and fun, but for those living with cardiovascular disease (CVD), winter can bring with it some risk. Research from the UK suggests that every 1°C reduction in temperature on a single day is associated with around 200 additional heart attacks.¹ Moreover, research from Sweden shows there is an estimated 37% increase in heart attacks on Christmas Eve alone,² but why?

Why Cold Weather Increases Cardiovascular Risk

Seasonal changes in temperature and the rise in contagious illnesses during the winter months, including influenza, can increase a person’s risk of heart attack if they already have CVD.^{3, 4, 5} Cooler temperatures are associated with some additional risk factors for CVD, and there are a few precautions people can take to protect their heart health in winter.

Can Cold Weather Affect Blood Flow and Blood Pressure?

Cold weather places physiological stress on our bodies. When it’s cold, our blood vessels constrict, or narrow, to minimise heat loss and maintain our core temperature.^{4, 5} This constriction can cause blood pressure to increase in cold weather, placing additional strain on the heart. This is one of the reasons many people notice their blood pressure is higher in winter compared to summer months.

Impact on Blood Viscosity and Clotting

Thermal stress due to a sudden drop in temperature can also affect platelet viscosity, making the blood thicker and more prone to clotting.³ This increases the risk of cardiovascular events and, in vulnerable individuals, can contribute to complications such as deep venous thrombosis (DVT). In rare cases, severe blood pressure spikes in winter have also been associated with aortic complications, including aortic rupture.

Protecting the Heart Through Warmth and Clothing

It is important to dress for the weather. Wearing layers of clothing that can be adjusted easily helps the body adapt to temperature changes and reduces the likelihood of thermal stress, which contributes to winter hypertension.⁵

Lifestyle Changes in Winter and Their Impact on CVD Risk

Every year, during winter and the festive season, people tend to change their lifestyle. For many, there is an increase in travelling, excessive food and alcohol consumption, and a tendency for people to fluctuate their exercise patterns significantly.³

Overexertion in Cold Temperatures

People can inadvertently overexert themselves in cooler temperatures, be it walking briskly through heavy winds or doing more strenuous physical activity to keep warm.⁶ This increases oxygen demand and creates additional strain on the heart. Staying active remains important, but balance and adequate recovery are essential.⁶

Seasonal Diet, Alcohol Intake and Heart Health

Richer meals and increased alcohol consumption are common during the festive period.⁷ For those with CVD, maintaining heart-healthy habits is essential to reduce unnecessary cardiovascular stress. Eating more fruit and vegetables, wholegrain, fatty fish, nuts and seeds can support heart health, while limiting foods high in saturated fat, trans fats, sodium and cholesterol can help stabilise blood pressure.⁷

Supporting Heart Health Through Balanced Activity and Rest

Staying physically active is a great way of keeping the body balanced and the heart healthy, but it is important to not overdo it and allow enough time to recover properly.⁶ Sleep is crucial because it helps the body regenerate whilst stabilising energy and appetite levels the next day.

The Risk of Delaying Medical Care

Winter and the festive season are peak periods for travel and visiting family, meaning that people tend to be away from their local healthcare teams, and sometimes for long periods of time. For those with CVD, not attending doctor appointments and/or delaying medical treatment for chest pains or respiratory viral infections, could lead blood pressure to spiral, increasing the risk of a heart attack.^{8, 9}

In addition to the biological, environmental and lifestyle impacts of winter on CVD risk, the festive season can cause psychological stress, contributing to higher blood pressure and aggravation of CVD risk factors.¹⁰

Additional Evidence on Winter Hypertension and Heart Attack Risk

Studies consistently show that colder temperatures lead to rises in both systolic and diastolic blood pressure. This is especially significant in older adults, individuals with hypertension and those living with chronic cardiovascular conditions. Seasonal spikes in blood pressure are a key reason why winter contributes to higher cardiovascular event rates, reinforcing the relationship between cold weather and hypertension.¹¹

Research also suggests that respiratory infections in winter, such as influenza, increase inflammatory activity in the bloodstream. This can destabilise arterial plaques, making heart attacks more likely in people with existing CVD. Vaccination, early symptom management and regular blood pressure monitoring therefore play a crucial role in winter heart-health protection.¹²

How Patients Can Stay Well During Winter

Understanding winter cardiovascular risk allows patients to take steps that protect their health:

Simple Measures to Reduce Risk

When to Seek Medical Help

It is important that patients listen to their bodies, and not delay making an appointment with their doctor or seeking immediate support. Patients that understand their blood pressure, cholesterol and blood sugar numbers can work with their doctors to keep them in the normal range.