Understanding "blood thinners"

These drugs actually help stop dangerous blood clots from forming. Here's when you may need them.

Nearly everyone has heard of "blood thinners." Maybe you or someone you know takes one. But these drugs don't "thin" blood at all.

"They are actually anti-clotting drugs," says Dr. Gregory Piazza, a cardiologist with Harvard-affiliated Brigham and Women's Hospital. "They prevent potentially dangerous blood clots from developing in people at high risk, like those who have atrial fibrillation or a stent in a blood vessel, or who are immobile after surgery."