Cardiologist explains why risk of heart attacks spikes during winters: ‘Your blood's clotting tendency increases…’

Due to seasonal adaptations and lifestyle changes, winters pose an increased risk of heart attacks. Dr Agrawal shares what you need to know.

As temperatures drop, heart attack cases quietly surge - a seasonal reality many people remain unaware of. The cold doesn’t just change the weather outside; it also triggers internal shifts in the body that can place extra strain on the heart. From altered blood flow to lifestyle changes during winter, these combined factors can significantly raise cardiac risk, making it especially important to stay alert to warning signs and seek medical help if something feels off.

Dr Navin Agrawal, an interventional cardiologist specialising in advanced heart procedures, has outlined six key reasons why the risk of heart attacks rises during the winter months. In an Instagram video posted on December 8, the cardiologist explains how the body’s natural adaptations to cold weather, along with seasonal lifestyle changes, collectively contribute to a higher risk of heart attacks during winter.

Why do heart attacks increase during winter?

Dr Agrawal explains that several of the body’s mechanisms are naturally altered during winter to adapt to colder temperatures - including changes in blood pressure, blood clotting, and blood vessel thickness - all of which can indirectly increase the risk of heart attacks. He outlines six key reasons why the risk of heart attacks rises significantly during the colder months.

Blood vessels constrict

According to Dr Agrawal, the blood vessels of the heart constrict during winters in order to adapt to the cold temperature, which naturally increases blood pressure. He explains, “Due to the low temperature during cold weather, the vessels of your heart constrict. Because of this, blood pressure naturally increases and your heart has to pump extra - it has to work harder. Because of this, the risk of a heart attack can increase.”

Increased clotting tendency

The cardiologist highlights that the blood’s natural clotting tendency increases during winter, making it thicker and more prone to clot formation - a change that significantly raises the risk of heart attacks. He states, “Furthermore, during the cold season, your blood's clotting tendency increases. The blood becomes slightly thick or viscous. This can cause problems.”

Viral infections

Dr Agrawal notes that winter is also the peak season for viral infections, which can weaken the body’s immune defences and simultaneously increase the blood’s tendency to clot, further elevating heart attack risk. He explains, “In addition, viral infections can occur in the body during winter. When any infection creates swelling or inflammation in the body, the clotting tendency increases.”

Reduced hydration

The cardiologist highlights that people often reduce their water intake during winter, leading to thicker blood consistency, which in turn makes it harder for the heart to pump efficiently and increases cardiac strain. He points out, “People often drink less water during the cold season. Drinking less water causes dehydration in the body, and because of this, people can often have a heart attack or cardiac arrest.”

Reduced physical activity

Regular movement and physical activity are among the most powerful protectors of heart health, yet during winter, many people become less active and spend longer periods cooped up indoors - a shift that can quietly elevate cardiovascular risk. Dr Agrawal explains, “During the cold season, people also reduce physical activity. This compromises circulation, and also increases the chance of a heart attack.”

High-fat foods

During winter, people often gravitate towards richer, high-fat foods and warming drinks to combat the cold - this seasonal shift can directly impact heart health. Dr Agrawal stresses, “During the cold season, people consume more high-fat food products and drinks. This also increases the body's clotting tendency.”

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. It is based on user-generated content from social media. HT.com has not independently verified the claims and does not endorse them.