Recent studies show that COVID-19 can be transmitted by infected persons who don’t know they have it because they have no symptoms, leading many states to require people to wear masks in public settings where distancing is difficult, like grocery stores. The biggest benefit is that the mask can decrease the risk of an infected person, whether or not they have symptoms, from spreading it to you. But wearing one can decrease your risk of catching it at least somewhat, along with social distancing and washing your hands. Plus, masks also remind others to keep their distance.