It is primarily older people and those who already have heart problems who have an increased risk of being affected when the temperature suddenly drops. And it does not seem to be the cold itself, but the temperature change that affects the heart.
In a study, published in the journal Journal of the American College of Cardiology, researchers have gone through data from 120,000 heart attacks in Sweden between October and March during the years 2005 to 2019.
Increased after two days of cold
The researchers compared the patients' places of residence with weather data from SMHI. Then they saw that the number of heart attacks increased after it had been cold for two days in a row. The connection was not affected by how cold it was initially, but by how large the temperature change was.
For example, if it was ten degrees and the next day it became minus five degrees, the number of heart attacks did not increase the first day. But if the cold persisted for a few days, the risk of heart attack increased. The largest risk increase was seen between day two and six with cold. The average age of the people who suffered from heart attack was 71 years.
The stress system is activated
From this type of register study, it is not possible to conclude that it is the cold that triggers the heart attack, only that a connection is seen. But according to the researchers, the reason why the risk of heart attack increases in cold weather would be that the body's stress system is activated to keep us warm. This leads to blood vessels constricting, which in turn increases blood pressure and makes the heart beat faster. In the end, the strain can become too great, not least for those who already have heart and vascular problems.
The study is based on data from the Swedish quality register Swedeheart, which is financed, among other things, by the Heart-Lung Foundation.
These are some common symptoms of a heart attack:
severe pain in the chest all the time and the pain can radiate to the arms or back
an unpleasant feeling or pressure in the chest that can also radiate to the neck, jaw, and shoulders
you may have difficulty breathing and feel cold sweat
you may feel scared and have anxiety
palpitations and dizziness
symptoms similar to influenza and simultaneously chest pain
nausea or vomiting
In 2023, there were approximately 22,200 cases of acute heart attack. It is roughly twice as common for men to be affected as for women, both in terms of falling ill and dying in connection with acute heart attack.
Source: 1177, National Board of Health and Welfare
