The CDC is reporting about two-thirds of the United States is reporting either "high" or "very high" activity levels.
Illinois is among those reporting high activity levels.
So far this season, more than 6.2 million people have reported getting the flu and 53,000 have been hospitalized.
Doctors at Rush said they are seeing an uptick in flu-like symptoms coming into their emergency room.
That is why they are encouraging people to get their flu shots.
Walgreens told ABC7 that certain stores are experiencing shortages of the prescribed anti-viral drug Tamiflu.