Influenza (also known as the flu) is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness. Symptoms include fever, cough, sore throat, runny or stuffy nose, muscle aches, and headache. Children commonly experience vomiting and diarrhea, as well. Serious outcomes of flu infection can result in hospitalization. Examples of complications from flu include pneumonia, ARDS, exacerbation of underlying conditions, bronchitis, and sometimes death. Some people, such as older people, young children, and people with certain health conditions (including, but not limited to, are diabetes, asthma, cardiovascular disease, and pregnancy) are at high risk for serious flu complications. The best way to prevent the flu is by getting vaccinated each year. Each year a new vaccine combination, based on surveillance data from the previous year, is distributed. Because it takes two weeks for immunity to build up, it is best to get your vaccine in October, before flu season begins. Although, you can still receive the flu vaccine throughout the flu season.

Types of Influenza Diseases:

Last reviewed December 2017