“We don’t talk about this too much, because we don’t want people to be afraid of these treatments,” says Dr. Doris Day, a board-certified dermatologist in New York City. “There are millions of injections done every year, and very few lead to serious complications. But this is an important conversation to have—as is the discussion around how we minimize the risks.”

Before your next filler appointment, familiarize yourself with the little-known pitfall that is vascular occlusion—so you might caption your experience Knowledge is power.