The findings in the journal Stroke do not prove alcohol and infections are triggers. But the review shows that people who had the equivalent of three-to-four drinks had a near tripling in the risk of stroke over 24 hours.
Catching a cold or flu was linked with a two-to-three fold increase in suffering a stroke over the next week or month.
In theory, researchers say, drinking could cause heart rhythm disturbances that dislodge a blood clot. Infections could also contribute to these disturbances or they may have inflammatory effects on the blood vessels.