The common cold, also known as an upper respiratory infection (URI), can be caused by more than 200 viruses.  These viruses attack and multiply in the cells that line the nose and throat.



The flu is a contagious respiratory illness caused by influenza viruses.  It can cause mild to severe illness, and at times can lead to death

Colds and flu are often mistaken for each other because they have similar symptoms and treatments. Please see below to learn more about cold and flu symptoms, treatment, and transmission