Moyo StudioGetty Images Winter is the season that most people usually get sick. But this year, even the slightest sniffle or congestion can have you worried that you have COVID-19. Sooo...how the heck do you figure out if you are dealing with a sinus infection or COVID-19 anyway? Asked and answered. We tapped cold and flu experts to decipher the difference between a sinus infection and COVID-19, and when you should go see your doctor to confirm what's *really* going on. What is a sinus infection? "Sinusitis or rhinosinusitis, commonly known as a sinus infection, is an inflammation in the nasal cavity and paranasal sinuses," says Kavita Shanker-Patel, MD, a family medicine physician at Northwestern Medicine Central DuPage Hospital. "A sinus infection typically lasts less than four weeks."