Influenza, commonly known as the flu, is an infectious disease caused by an influenza virus. Symptoms can be mild to severe. The most common symptoms include: high fever, runny nose, sore throat, muscle pains, headache, coughing, sneezing, and feeling tired.
Influenza Updates: Flu activity in the U.S. is low now, but expected to pick up in the coming weeks. CDC on Flu Vaccine: CDC’s vaccine recommendations for the 2018-2019 flu season are now available.; CDC recommends yearly flu vaccination for people 6 months and older.
Influenza viruses cause the flu and are divided into three types, designated A, B, and C. Influenza A and influenza B are responsible for epidemics of respiratory illness that occur almost every winter and are often associated with increased rates of hospitalization and death. Influenza type C differs from types A and B in some important ways.
The flu is a highly contagious and common illness that is caused by the influenza virus. There are three different types of flu viruses: influenza A, B, and C, all of which cause illness in humans.
Ask The Expert: Influenza Q&A
Flu is a respiratory infection caused by a number of viruses. The viruses pass through the air and enter your body through your nose or mouth. Between 5% and 20% of people in the U.S. get the flu each year.