Influenza, or "flu," is a highly contagious respiratory illness caused by flu viruses that infect the nose, throat and sometimes the lungs. While flu viruses can be detected year-round in the United States, they are most common during the fall and winter, with activity increasing in October and peaking between December and February.1
Each year, an estimated 3-11% of the U.S. population gets the flu, and it can be very serious, resulting in hospitalization or even death.2,3 Since 2010, the Centers for Disease Control and Prevention (CDC) estimates that the flu has resulted in:4,5
Flu symptoms start abruptly and are severe, whereas cold symptoms come on gradually.6 Common flu symptoms include fever or chills, cough, sore throat, muscle or body aches, runny nose, headaches and fatigue.6
Over-the-counter (OTC) cold medicines can temporarily relieve flu symptoms, but antiviral treatments attack the flu at the source, stopping the virus from spreading in the body to get you on a quicker path to recovery.6,7
The flu is highly contagious and is transmitted when someone coughs, sneezes or talks.3 It can also live on some surfaces for up to 48 hours, and can spread if someone touches the surface and then touches their mouth or nose.8
Most healthy adults may be able to spread the flu as early as one day before their symptoms develop and up to 6-7 days after becoming sick.3
The CDC recommends that all persons aged six months and older should be vaccinated annually. Talk to a healthcare provider to see if it is right for you.9
Routinely clean surfaces, steer clear of people who are sick, cover your mouth when you cough or sneeze and wash hands frequently.3
Antiviral medicines help reduce the duration of flu symptoms and are most effective if taken within 48 hours of symptom onset.6
If you experience sudden flu symptoms, call your doctor within 48 hours to learn about treatment options.
*Centers for Disease Control and Prevention statistics from 2010-2016 influenza seasons
†Centers for Disease Control and Prevention statistics from 2010-2017/18 influenza seasons
1 Centers for Disease Control and Prevention (2016, July 26). The Flu Season. Retrieved June 20, 2018, from: https://www.cdc.gov/flu/about/season/flu-season.htm.
2 Tokars JI, Olsen SJ, Reed C. Seasonal incidence of symptomatic influenza in the United States. Clin Infect Dis. 2018;66: 1611-8.
3 Centers for Disease Control and Prevention. (2017, October 3). Key Facts About Influenza (Flu). Retrieved June 20, 2018, from: https://www.cdc.gov/flu/keyfacts.htm.
4 Rolfes MA et al. Annual estimates of the burden of seasonal influenza in the United States: A tool for strengthening influenza surveillance and preparedness. Influenza Other Respi Viruses; 2018;12:132–137.
5 National Foundation for Infectious Diseases. Influenza and pneumococcal disease can be serious, health officials urge vaccination. Retrieved October 5, 2018, from: http://www.nfid.org/newsroom/news-conferences/2018-nfid-influenza-pneumococcal-news-conference/press-release.pdf.
6 Cleveland Clinic (2016, October 3). Is It a Cold or the Flu? Know Your F.A.C.T.S. (Infographic). Retrieved August 8, 2018, from: https://health.clevelandclinic.org/is-it-a-cold-or-the-flu-know-your-f-a-c-t-s-infographic/.
7 Centers for Disease Control and Prevention (2017). Treating Influenza (Flu). Retrieved August 17, 2018, from: https://www.cdc.gov/flu/pdf/freeresources/updated/treating-influenza-2017.pdf.
8 Centers for Disease Control and Prevention. (2018). Cleaning to Prevent the Flu. Retrieved July 2, 2018, from: https://www.cdc.gov/immigrantrefugeehealth/pdf/seasonal-flu/contamination_cleaning_english_608.pdf.
9 Centers for Disease Control and Prevention. (2018). Get Vaccinated. Retrieved August 8, 2018, from: https://www.cdc.gov/flu/consumer/vaccinations.htm.