About 5% to 20% of the U.S. population gets the flu every year. The CDC estimates that there have been 9 to 41 million flu illnesses a year between 2010 and 2020.

While getting vaccinated is the most effective way of avoiding the flu, understanding how the flu spreads is a big step towards prevention.

Read a few helpful tips to prevent seasonal influenza.

Certain people may have higher risk factors for influenza complications.