1. Foods to Eat When You Have the Flu Slideshow
2. Natural Cold and Flu Remedies Pictures
3. Finding Relief for Your Cough Slideshow

Medical Author:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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In this Article

• Flu (influenza, conventional, and H1N1) facts
• What is influenza?
• What are the causes of the flu?
• What are flu symptoms in adults and in children?
• How is the flu diagnosed?
• What is the key to flu prevention?
• Are there any flu shot or nasal spray vaccine side effects in adults or in children?
• Why should the influenza vaccine be taken every year?
• What are some treatments an individual can do at home for the flu?
• When should a person go to the emergency department for the flu?
• Who should receive the flu vaccine, and who has the highest risk factors? When should someone get the flu shot?
• What is the prognosis (outlook) and complications for patients who get the flu?
• What is the bird (avian) flu?
• Do antiviral agents protect people from the flu?
• Is it safe to get a flu shot that contains thimerosal?
• Where can I find additional information about the flu?
• Slideshow: Foods to Eat When You Have the Flu
• Slideshow: Natural Cold & Flu Remedies
• Slideshow: Finding Relief for Your Cough
• Patient Comments: Flu (Influenza) - Symptoms
• Patient Comments: Flu (Influenza) - Side effects
• Influenza Index

In the United States, the flu season usually occurs from about November until April. Officials have decided each new flu season will start each year on Oct. 4. Typically, activity is very low until December, and peak activity most often occurs between January and March. Ideally, the conventional flu vaccine should be administered between September and mid-November. It takes about one to two weeks after vaccination for antibodies against influenza to develop and provide protection. The CDC has published a summary list of their current recommendations of who should get the current vaccine:

Summary of influenza vaccination recommendations

• All people 6 months and older should be vaccinated annually, unless they have a rare and specific contraindication (for example, severe egg allergy, previous severe reaction to the vaccine, certain neurologic problems).
• Protection of people at higher risk for influenza-related complications should continue to be a focus of vaccination efforts as providers and programs transition to routine vaccination of all people 6 months and older.
• When vaccine supply is limited, vaccination efforts should focus on delivering vaccination to people who
• are 6 months to 4 years (59 months) of age;
• are 50 years of age and older;
• have chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorder (including diabetes mellitus);
• are immunosuppressed (including immunosuppression caused by medications or by human immunodeficiency virus);
• are or will be pregnant during the influenza season;
• are 6 months to 18 years of age and receiving long-term aspirin therapy and who therefore might be at risk for experiencing Reye's syndrome after influenza virus infection;
• are residents of nursing homes and other chronic-care facilities;
• are American Indians/Alaska natives;
• are morbidly obese (body mass index is 40 or greater);
• are health care professionals;
• are household contacts and caregivers of children aged younger than 5 years and adults aged 50 years and older, with particular emphasis on vaccinating contacts of children aged younger than 6 months;
• are household contacts and caregivers of people with medical conditions that put them at higher risk for severe complications from influenza.

As each flu season progresses and as the CDC refines its data from previous flu seasons and pandemics, this summary may be modified. The CDC publishes routine updates about the flu at Flu.gov and at http://www.cdc.gov/flu/weekly/fluactivity.htm.