The flu is a respiratory (i.e., nose, throat and lung) infection that can be caused by a variety of influenza viruses. Many people use the word "flu" when they actually have a cold. Although the common cold is also caused by viruses, the flu and common cold differ in several ways.
It's important to recognize the difference, not just because they require different treatment but because
a flu can be a much
greater health concern because it has the potential to lead to serious complications. Can you tell the difference? Test your knowledge!