Overview

Influenza is a viral infection that attacks your respiratory system — your nose, throat and lungs. Influenza, commonly called the flu, is not the same as stomach "flu" viruses that cause diarrhea and vomiting.

For most people, influenza resolves on its own. But sometimes, influenza and its complications can be deadly. People at higher risk of developing flu complications include:

  • Young children under 5, and especially those under 2 years
  • Adults older than 65
  • Residents of nursing homes and other long-term care facilities
  • Pregnant women and women up to two weeks postpartum
  • People with weakened immune systems
  • People who have chronic illnesses, such as asthma, heart disease, kidney disease and diabetes
  • People who are very obese, with a body mass index (BMI) of 40 or higher

Your best defense against influenza is to receive an annual vaccination.

Oct. 20, 2016
References
  1. Longo DL, et al., eds. Influenza. In: Harrison's Principles of Internal Medicine. 19th ed. New York, N.Y.: The McGraw-Hill Companies; 2015. http://accessmedicine.com. Accessed Aug. 12, 2016.
  2. Frequently asked questions 2016-2017 influenza season. Centers for Disease Control and Prevention. http://www.cdc.gov/flu/about/season/flu-season-2016-2017.htm. Accessed Aug. 12, 2016.
  3. ACIP votes down use of LAIV for 2016-2017 flu season. Centers for Disease Control and Prevention. http://www.cdc.gov/media/releases/2016/s0622-laiv-flu.html. Accessed Aug. 12, 2016.
  4. Dolin R. Clinical manifestations of seasonal influenza in adults. http://www.uptodate.com/home. Accessed Aug. 12, 2016.
  5. Zachary KC. Treatment of seasonal influenza in adults. http://www.uptodate.com/home. Accessed Aug. 12, 2016.
  6. Ferri FF. Influenza. In: Ferri's Clinical Advisor 2017. Philadelphia, Pa.: Elsevier; 2017. https://www.clinicalkey.com. Accessed Aug. 12, 2016.
  7. The flu: What to do if you get sick. Centers for Disease Control and Prevention. http://www.cdc.gov/flu/takingcare.htm. Accessed Aug. 12, 2016.
  8. Centers for Disease Control and Prevention, et al. Prevention and control of influenza with vaccines: Recommendations of the advisory committee on immunization practices, United States, 2016-17 influenza season. MMWR. 2016;65:1. https://www.cdc.gov/mmwr/volumes/65/rr/rr6505a1.htm?s_cid=rr6505a1_w. Accessed Aug. 26, 2016.