There’s lots of confusion out there about the differences between viral respiratory illnesses Yul Ejness, MD, tells NPR.
There are some clear distinctions between the two similar types of viral illness in terms of symptoms — how quickly they appear and how severe they become.
Flu symptoms, Ejnes says, usually start abruptly — though you can spread the virus before symptoms surface. A cold, on the other hand, takes a couple of days to build up. You may have a scratchy throat one day and then the nose starts to get stuffy the next day.