Just two days after a doctor told her she was merely stressed out, Stacey Yepes pulled over to film a selfie video because, for the third time in three days, the Canadian woman felt one side of her face go numb. The move may have saved the 49-year-old's life; doctors at another Toronto hospital used the footage to help diagnose a transient ischemic attack, or mini stroke, as a result of plaque that had built up in her arteries. A sizable 87% of all strokes are ischemic, the Washington Post notes. "The sensation is happening again," she told the camera in April, her words slurred. "It's all tingly on the left side. ... I don't know why this is happening to me."
While Yepes' selfie armed doctors with the information they needed to make the diagnosis, one doctor with the World Stroke Foundation tells CNN she was lucky, because when it comes to strokes, time is paramount: "Don't waste time on a video, just call 911." The American Stroke Association instructs people to look out for FAST—face drooping, arm weakness, speech slurring, and time (as in, don't waste it; dial 911). As for Yepes, she's on on cholesterol-lowering medication and blood thinners, and hasn't had any mini-strokes since. (Click to read why new guidelines say women need to be better than men about tracking their stroke risk.)