About the flu
Influenza, commonly called the "flu", is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness and, at times, can lead to death. Although most healthy people recover from the flu without complications, some people, such as older people, young children, and people with certain health conditions, are at high risk for serious complications from the flu.
How do I know if I have the flu?
The flu usually starts suddenly and may include the following symptoms:
- Fever (usually above 100 degrees)
- Sore throat
- Runny or stuffy nose
- Body aches
- Fatigue (tiredness)
- Diarrhea and vomiting (more common among children than adults)
What are the risks?
In some people, the flu can cause serious complications, including bacterial pneumonia, dehydration, and worsening of chronic medical conditions such as congestive heart failure, asthma, or diabetes. Children and adults may develop sinus problems and ear infections.
How is the flu spread?
The flu usually spreads from person to person in respiratory droplets when people who are infected with a flu virus cough, sneeze, or talk. These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs. A person may also get the flu by touching a surface or object with a flu virus on it and then touching their mouth, nose, or eyes. Healthy adults may be able to infect others one day before getting symptoms and up to five to seven days after getting sick. Therefore, it is possible to give someone the flu before you know you are sick as well as while you are sick.
How can I avoid spreading the flu?
Some simple hygienic behaviors that can help prevent the spread of respiratory illnesses such as the flu are:
- Cover your nose and mouth with a tissue when you cough or sneeze--throw the tissue away after you use it.
- Wash your hands often with soap and water, especially after you cough or sneeze. If soap and water are not available, use an alcohol-based hand rub.
- Avoid close contact with people who are sick. When you are sick, keep your distance from others to protect them from getting sick too.
- If you get the flu, stay home from work, school, and social gatherings. This will help prevent spreading your illness to others.
- Try not to touch your eyes, nose, or mouth. Germs often spread this way.
What about the flu vaccine?
The best way to protect yourself and others against the flu is to get a flu vaccine each year. A yearly flu vaccine is recommended for everyone 6 months and older without an increased risk for a serious adverse reaction. All of the 2017 - 2018 flu vaccines are made to protect against an influenza A (H1N1) virus, an influenza A (H3N2) virus, and one or two influenza B viruses, depending on the flu vaccine. Talk with your health care provider about which vaccine is right for you.
Three kinds of flu vaccine are available:
- Inactivated Influenza Vaccine (IIV) - an inactivated vaccine (containing killed viruses) that is given with a needle. The flu shot is approved for use in people 6 months of age and older, including healthy people, people with chronic medical conditions and pregnant women.
- Recombinant Influenza Vaccine (RIV) - a vaccine that does not use flu viruses or chicken eggs in its manufacturing process. RIV is also given with a needle and is approved for use in adults 18 years and older. This is the only vaccine currently available that is completely egg free.
- Live Attenuated Influenza Vaccine (LAIV) - a vaccine made with live, weakened flu viruses that do not cause the flu and is given intranasally (also known as the “nasal spray” vaccine). LAIV is approved for use in healthy people 2-49 years of age who are not pregnant. NOTE: The Centers for Disease Control and Prevention (CDC) and the Advisory Committee on Immunization Practices (ACIP) recommend that LAIV should not be used during the 2017-2018 flu season due to concerns about poor vaccine effectiveness.
You should receive a flu vaccine by the end of October, if possible. Vaccination should continue to be offered as long as flu viruses are circulating, even in January or later. While seasonal flu outbreaks can happen as early as October, during most seasons flu activity peaks in January or later. It is best to get vaccinated before flu viruses start to spread in your community since it takes about two weeks after vaccination for antibodies to develop in the body and provide protection against the flu.
Who should get a flu shot?
Everyone 6 months and older should get a flu shot each year if they do not have an increased risk for a serious adverse reaction. Vaccination is particularly important for people who are at high risk for developing serious complications from the flu or people who live with or care for those who are at high risk for flu complications.
Why is it important to get the flu shot every year?
Flu viruses are constantly changing, so the vaccines are reviewed and updated each year to keep up with the changing flu viruses. Additionally, the body’s immune response from vaccination declines over time, so an annual flu vaccine is needed for optimal protection.
What should I do if I get sick?
It is very difficult to distinguish the flu from other infections on the basis of symptoms alone. Most people with the flu have mild illness and do not need medical care. However, if you have symptoms of flu and are in a high risk group, or are very sick and worried about your illness, contact your health care provider. There are tests that can determine if you have the flu. There are also drugs your doctor may prescribe for treating the flu called antivirals.
If you get the flu, get plenty of rest, drink a lot of liquids, and avoid using alcohol and tobacco. Also, you can take medications such as Tylenol to relieve the fever and muscle aches associated with the flu. Never give aspirin to children or teenagers who have flu-like symptoms, particularly fever. Stay home for at least 24 hours after your fever is gone without the use of a fever-reducing medicine, except to get medical care or other necessities.
People age 65 and older and those with chronic medical conditions such as heart disease and diabetes should discuss the pneumococcal vaccine with their health care provider. The vaccine is effective in preventing many types of pneumonia, one of the major complications from the flu.
For Additional Information:
- Seasonal Influenza
- Pandemic Influenza
- Seasonal Influenza: Flu Basics (CDC)
- Preventing Seasonal Flu With Vaccination (CDC)
- Questions & Answers: Vaccine Effectiveness (CDC)
- Good Health Habits for Preventing Seasonal Flu (CDC)>
- Treating Seasonal Flu With Antiviral Drugs (CDC)
- Misconceptions about Seasonal Flu and Flu Vaccines (CDC)