NEW YORK — When we think about the flu, we think about the high fever, runny nose, and brutal body aches that come with the illness. But new research gives us something far more alarming to think about: contracting the flu and flu-like illnesses increases one’s risk of suffering a stroke and neck artery tears.
Researchers from Columbia University arrived at the frightening conclusions following two preliminary studies.
The first study found that battling a flu-like illness boosts a person’s risk of having a stroke by about 40% in the 15 days after coming down with the ailment. Though the risk decreased over time, but overall, the likelihood remained heightened for up to one year.
The researchers looked at data from 30,912 patients who suffered an ischemic stroke in New York between 2012 and 2014 and compared each patient’s “case window,” or the time preceding the stroke, to a control set of time periods using the same dates from the previous two years. The results were ordered by urban and rural status using residential zip code, as well as by sex and race.
“We were expecting to see differences in the flu-stroke association between rural and urban areas. Instead we found the association between flu-like illness and stroke was similar between people living in rural and urban areas, as well as for men and women, and among racial groups,” notes lead author Dr. Amelia K. Boehme, an assistant professor of epidemiology in neurology at the university, in a release by the American Heart Association.
Researchers don’t know why the increased risk of stroke occurs after battling the flu. The leading hypothesis concerns the inflammation that comes with flu symptoms.
In the second study, another group of researchers from Columbia calculated the associated risk of cervical artery dissection (neck artery tears) within one month of contracting the flu by reviewing 3,861 cases from 2006 through 2014. After finding 1,736 instances of flu-like illness and 113 cases of flu during the three years preceding the dissection, the authors calculated that patients who suffered the devastating tears were more likely to have suffered from the flu or a flu-like illness within 30 days prior to the artery tear.
“Our results suggest that the risk of dissection fades over time after the flu. This trend indicates that flu-like illnesses may indeed trigger dissection,” says lead author Madeleine Hunter, a second-year medical student at the university.
Doctors suggest that individuals get a flu shot every year to lower the risk of contracting the ailment and the potential conditions that could comes as a result.
“If you do have the flu and you start having other symptoms that are consistent with stroke, such as weakness of the face, arm, or leg on one side or both, trouble speaking, slurred speech, loss of vision in one or both eyes, the worst headache of your life, or staggering around, you could have a dissected artery or some other cause of stroke,” Dr. Philip B. Gorelick tells the AHA. “I think people should consider taking a flu shot. It’s been shown in some other studies that if you take the flu shot, you’re less likely to get a stroke, so that would be good news.”
These studies were presented separately at the American Stroke Association’s International Stroke Conference 2019.