If you are an older adult with diabetes, high blood pressure, atrial fibrillation, high cholesterol or migraine, you likely know that you are at higher risk for stroke. But did you know that an infection also may boost your odds of having a stroke?

While it’s been known by scientists that a nasty urinary tract infection or respiratory infection may increase one’s vulnerability to a life-threatening stroke, questions have remained around the specific types of stroke that may be triggered by different infections.

Now: To find out exactly which infections most often preceded three types of strokes, researchers at the Icahn School of Medicine at Mount Sinai in New York City delved further into the data.

Study details: For their study, researchers searched databases at New York state hospitals and analyzed admissions for three types of stroke along with hospital or emergency room admissions for five types of infection.

Ischemic stroke, the most common type of stroke, which is typically caused by a blood clot that blocks blood supply to the brain…intracerebral hemorrhage, due to bleeding into the brain…and subarachnoid hemorrhage, resulting from bleeding in the inner lining of the brain, were the types of stroke studied.

In addition, the researchers looked at five types of infection—skin…urinary tract…sepsis (a life-threatening infection of the bloodstream)…abdominal…and respiratory (including pneumonia and other lung infections). The odds of an infection triggering a stroke seven to 120 days after infection were then calculated.

Study results: Every type of infection included in the study increased the odds of an ischemic stroke. Urinary tract infection had the strongest association, increasing the risk by threefold within 30 days after infection.

For intracerebral hemorrhage, urinary tract and respiratory infections and sepsis increased risk. This time, the strongest association was found with sepsis, which tripled the risk within 60 days after infection.

Only a respiratory infection increased the risk for subarachnoid hemorrhage. This infection tripled the risk in the shortest period of time—within 14 days.

The good news is, with all types of infection studied, the risk for any stroke decreased over time.

The researchers theorized that various factors could be at play. People who develop infections may be more likely to suffer a stroke because the infection leads to inflammation that damages blood vessels…and increased numbers of white blood cells and platelets may contribute to the formation of blood clots. Infections also tend to make people less active, which also may increase the risk of blood clotting.

What this research could mean for you: The study did not analyze whether avoiding infection helps protect people from stroke. However, it’s always wise to guard against infection—regardless of one’s stroke risk.

During cold and flu season, for example, this includes avoiding illness-causing germs by washing your hands frequently, staying away from sick people and crowds whenever possible—and getting a flu shot and pneumonia vaccine. Warning signs of a urinary tract infection include chills, fever and burning pain when passing urine.

While it’s not known whether treating an infection promptly will tamp down any increased stroke risk, be sure to let your doctor know about any symptoms of infection right away.