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

Influenza is surging in the U.S., with doctor visits for flu symptoms at a 15-year high. Why is this flu season so bad?

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

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

Influenza A — a nasty flu strain that fueled the 2009 flu epidemic — has been landing Ohioans in the hospital since the ...

The CDC estimated there have been 24 million cases of the flu so far this season, leading to 310,000 hospitalizations and ...