Influenza can cause fever, chills, cough, sore throat, headache, and muscle aches.
The influenza virus is usually passed when an infected person coughs or sneezes and another person inhales droplets containing the virus. Although most people are ill for only a few days, some have much more serious illness and need to be hospitalized. Thousands of people die each year from influenza-related complications. Most influenza-related deaths are in the elderly. Anyone who wants to reduce their chance of catching influenza may receive the vaccination.