Influenza (flu)

Influenza (flu) is an infection, caused by a virus, that makes you feel very sick, often with fever, headache, body aches, and coughing.

People often use the term "flu" to describe a cold or a stomach virus. But influenza isn't a stomach problem (although some little children may have vomiting and diarrhea). And it usually feels much worse than a cold.

The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.