Does cold weather increase stroke risk?

By Published On: 15 December 2022

The UK has seen temperatures as low as -6 this week in some places and with the snowfall set to continue winter is truly here.

As many are facing the backlash of the cost of living crisis and have been left in an inhumane situation where decisions on whether or not heating can be afforded to put on, the same advice rolls out, wrap up and put the heating on in living spaces and bedrooms. 

Despite however patronising this advice may seem, Dr Mark Porter explains in The Times the science behind these warnings and why the likes of the NHS issue them.

“Lower temperatures (anything below 12C), and particularly cold snaps like this, eat a significant toll on the nation’s health and put an already stained NHS under even more pressure.”

The freezing temperatures of course bring the risk of broken bones, with slippy surfaces adding to the risk of your daily commute, however it is “the effects on the cardiovascular system that tend to cause the most concern.”

Statistics from the NHS says that heart problems account for about 40 per cent of excess deaths seen during the winter months. Additionally, a study funded by the British Heart Foundation, carried out by scientists at the University of Bristol and University College London, discovered that heart attacks and strokes were more than twice as likely to happen during cold spells lasting at least four days.

In this study, they defined a cold spell as a period that was ‘particularly cold compared to the rest of the month.’ They found that the biggest factor was a fall in temperature compared to the days previous, rather than exactly how cold it was.

The British Heart Foundation also warn that individuals with angina may experience ‘a worsening in their symptoms during the winter months’. They reiterate that it is important to stay warm if you gave a heart condition, as the cold can cause blood to become thicker and stickier and more likely to form clots.

Dr Porter warns against seasonal variations in behaviour, he says: “We tend to eat less healthily and be more sedentary during the winter, piling on a few pounds over the festive season. 

“We also spend more time inside mixing in close proximity to others, which encourages the spread of respiratory infections that may also play a role (not least Covid, which has been shown to increase the risk of stroke, heart attack and blood clots for months after recovery).”

Dr Porter also says to not push yourself too hard during outdoor exercise “particularly after a large meal (like Christmas lunch), which divers blood to the gut and away from the heart.

“No one wants to end up in their local emergency department at the moment.”

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