If it seems as if everyone is sick, you may be right as the Centers for Disease Control and Prevention said that the flu is surging.

The winter flu season features two types of influenza. Here's what you need to know about them and how they differ.

Influenza levels in the US are the highest they've been in 15 years amid winter weather and a second wave of the virus.

Flu infections are at or near their highest levels in at least 15 years and are still rising, the Centers for Disease Control and Prevention says.

The U.S. winter virus season is in full force, and by one measure is the most intense in 15 years.

Data on flu test positivity and Tamiflu prescription fills show that influenza activity has already surpassed the past 7 ...