Doctor's visits for flu symptoms are at a 15-year high. Why is this flu season so bad? Doctors discuss flu severity, symptoms and how to stay safe.

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

When H5N1 first came to the attention of infectious disease professionals 20 years ago, there was concern it could mutate and ...

Yahoo News provides the latest updates on the spread of bird flu in the U.S., and its effect on rising egg prices and ...

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