Growing up in sunny Southern California, this rarely happened—mostly just on ski trips or when I’d spend too long in the ocean. (Yes, I realize how obnoxious that sentence is.) But when I moved to New York for college five years ago, my blue hands became a winter mainstay. I’d never lived in a cold climate, so I assumed this happened to everyone in frigid weather.

Turns out I assumed wrong. On a trip to Chicago to visit extended family this past Thanksgiving, I went for a walk and returned to my aunt’s house with my signature blue fingers. “Oh, you must have Raynaud’s,” my aunt said. I must have what?

Naturally, I headed back to New York with a lot of questions, so I called up Melisa Lai Becker, MD, site chief of emergency medicine at Cambridge Health Alliance in Everett, Mass. Dr. Lai Becker described my experience as “the classic vignette that would open a textbook chapter on Raynaud’s disease.” (By the way, it’s pronounced ray-NOHZ.) So if you’re concerned you might also have Raynaud’s, here’s some info and advice from Dr. Lai Becker to help you (and me) out.