Doctors are urging you to get prepared for flu season, by taking a look back at years past.
"Last year was the most severe flu season in over a decade," said Dr. Harry Leider, the chief medical officer at Walgreen's.
Leider says when you run the numbers, Americans missed a collective 230 million days of work while out sick in 2012 -- losing out on $8.5 billion in wages. Two to three times more than what's typical.
"The reason it was so bad last year was it hit early," Leider said.
The flu peaked around December and a lot of people were not vaccinated, Leider said.
Children missed an estimated 91 million days of school.
And those who got sick, spread the virus to friends and family. Flu seasons are hard to predict and Leider says the best defense is a good offense -- that means getting your flu shot now.
"The best protection is not to predict the future, but to get vaccinated early, and now is a great time," Leider said.