Can the season really affect the heart?
It doesn’t seem like the outside temps should affect your ticker, but research shows a link between cold weather and heart failure risk. One U.S. study looking at about 600,000 heart failure hospitalizations over three years found that the likelihood having longer, more expensive hospital stays—as well as dying—spiked in winter. A Canadian study of about 113,000 heart failure patients 65 and older reports that for every 1°C (1.8°F) the average temperature drops, heart failure risk increases by 0.7 percent. So going from 75°F to 32°F, for instance, would increase risk by about 17 percent. There are a number of reasons why your heart is more vulnerable in cold weather, from higher rates of infection to the stress of cold on the body. Heart failure is not the same as heart attack; it usually develops gradually, as the heart muscle becomes weaker and has trouble pumping blood to the cells in the body. Heart attacks happen more suddenly, when an artery becomes blocked and cuts off blood flow, often after a piece of plaque breaks off and forms a blood clot. Heart attacks weaken the heart and can lead to heart failure. These are the times heart attacks are more likely to occur.
Your blood vessels constrict
When your body is working to keep you warm, it focuses most on protecting vital organs like the brain and lungs from extreme temperatures. One of its responses is to constrict blood vessels, making it harder for blood to reach your whole body. “It’s trying to preserve blood flow to your vital organs,” says Martha Gulati, MD, cardiologist at the University of Arizona and editor-in-chief of CardioSmart.org. That means your heart needs to beat harder and faster to supply your body with the oxygen it needs, she says. For instance, walking down the block may be easy breezy in the springtime, but the same distance can leave your heart pounding when it’s cold out. As your heart rate and blood pressure increase, you raise your risk of blood clots, stroke, and heart attack. Protect yourself by dressing warm—especially making sure your hands, feet, and head, which can lose a lot of body heat, are covered—so your heart doesn’t have to work so hard to regulate your temperature, says Dr. Gulati.