Flu and Respiratory Virus Protection

General Frequently Asked Questions About Flu and Respiratory Viruses

The flu and other respiratory viruses can cause mild to severe illness. There are ways to protect yourself from illness and lessen the likelihood of spreading the viruses. Below are some general questions and answers about the flu and other respiratory viruses.

For more information about the flu, see the CDC's website.

Frequently Asked Questions

1. What is influenza (flu)?
2. What are the signs and symptoms of the flu?
3. How does the flu spread?
4. How long are people contagious?
5. When do symptoms begin?
6. How long are people sick with the flu?
7. What are some of the complications of the flu?
8. Which people are at high risk at contracting the flu?
9. How do you prevent the flu?
10. What's the best method to wash your hands?
11. Who should get vaccinated?
12. When should you get vaccinated?
13. How do you know it's the flu?
14. Is there a treatment for the flu?
15. What should you do if you get the flu?
16. What's new for the influenza season?
17. What about avian flu?
18. What about wearing a disposable N95 respirator?


1. What is influenza (flu)?
The flu is a contagious respiratory illness caused by the influenza virus that infects the nose, throat and lungs. It can cause mild to severe illness and can even lead to death. There are numerous strains of the influenza virus, and the flu is different from a cold.


2. What are the signs and symptoms of the flu?
People who have the flu often feel some or all of these signs and symptoms:

  • Fever or feeling feverish and chilled
  • Cough
  • Sore throat
  • Runny or stuffy nose
  • Muscle or body aches
  • Headaches
  • Fatigue
  • Vomiting and diarrhea (more common in children than adults)

3. How does the flu spread?
The flu spreads from person to person. Most experts believe flu viruses are transmitted primarily by droplets of saliva made when people with the flu cough, sneeze or talk. These droplets can land in the mouths or noses of people who are up to six feet away. Although less likely, a person might also get the flu by touching a surface or object that has the flu virus on it and then touching their own mouth, eyes or nose.


Back to Top


4. How long are people contagious?
You may be able to pass the flu on to someone else before you even know you are sick, as well as while you are sick. Most healthy adults are contagious one day before symptoms develop and between five to seven days after becoming sick. Some people, especially young children and people with weakened immune systems, might be able to infect others for an even longer period of time.


5. When do symptoms begin?
Symptoms begin to show between one and four days from the time a person is exposed to the flu virus. The average is about two days after exposure.


6. How long are people sick with the flu?
Most people who get influenza will recover any time within days to about two weeks.


Back to Top


7. What are some of the complications of the flu?
A wide range of complications can be caused by the influenza virus, including upper respiratory tract infections (nasal passages and throat) and lower respiratory tract infections (lungs). Sinus and ear infections are examples of moderate complications from the flu, while pneumonia is a more serious complication. Other possible serious complications triggered by the flu include inflammation of the heart, brain or muscle tissues, and multiple organ failure. The flu can also worsen chronic medical conditions, like congestive heart disease, asthma or diabetes.


8. Which people are at high risk at contracting the flu?
Anyone, even healthy people, can get the flu, and serious problems related to the flu can happen at any age. However, some people are at a higher risk of developing serious flu-related complications if they get sick. This population includes people 65 years or older, people of any age with certain chronic medical conditions such as asthma, diabetes or heart disease, pregnant women and young children.


9. How do you prevent the flu?
The first and most important step in preventing the flu is to get a flu vaccination each year. The CDC also recommends everyday preventative actions, such as:
  • Staying away from people who are sick
  • Covering coughs and sneezes
  • Frequent handwashing with soap and water or an alcohol-based hand rub if that’s the only option to help slow the spread of germs that cause respiratory illnesses like the flu
Frequently touched surfaces should also be cleaned and disinfected at home, work and school, especially if someone is ill.


Back to Top


10. What's the best method to wash your hands?
Washing your hands often will help protect you from germs. When washing your hands with soap and water, you should wash the back, palm and fingers thoroughly for 15 to 20 seconds and rinse them under a stream of water. An alcohol-based hand sanitizer is a good substitute when soap and water are not available. Just rub your hands together until dry.


11. Who should get vaccinated?
Everyone six months of age or older should get a flu vaccine every season. Vaccinations to prevent influenza are particularly important for people who are at high risk of serious complications from influenza. Flu vaccinations can reduce flu illnesses, doctor’s visits and missed work or school due to the flu.


12. When should you get vaccinated?
The CDC recommends people get vaccinated against the flu soon after the vaccine becomes available, if possible by October. It takes about two weeks after vaccination for the antibodies to develop in the body and provide protection against the flu.


Back to Top


13. How do you know it's the flu?
It is very difficult to diagnose the flu from other viral or bacterial causes of respiratory illness on the basis of symptoms alone. There are tests that can be administered by medical professionals to diagnose the flu.


14. Is there a treatment for the flu?
There are influenza antiviral drugs that can be used to treat the flu. Antiviral drugs are different from antibiotics. They are prescribed medicines (pills, liquid or an inhaled powder) and are not available over-the-counter. Antiviral drugs can make the illness milder and shorten the time you are sick, and they may prevent serious flu complications. Flu antiviral drugs work best for treatment if started within two days of getting sick, although starting later can still be helpful. Most otherwise healthy people who get the flu do not need to be treated with antiviral drugs.


15. What should you do if you get the flu?
If you get the flu, there are some basic steps you should take. They include:
  • Take antiviral drugs, if prescribed by a doctor
  • Initiate everyday precautions to protect others while you are sick: limit contact with other people; cover your nose and mouth with a tissue when sneezing or coughing and then properly dispose of the tissue; wash your hands with soap and water or an alcohol-based rub; and clean and disinfect surfaces that may be contaminated with germs
  • Stay home until you are better; the CDC recommends at least 24 hours after your fever is gone, except to get medical care or other necessities

Back to Top


16. What's new for the influenza season?
The CDC has recommended the trivalent vaccines for use in the 2016-17 influenza season (winter in the Northern Hemisphere) contain the following:
  • A/California/7/2009 (H1N1)pdm09-like virus
  • A/Hong Kong/4801/2014 (H3N2)-like virus
  • B/Brisbane/60/2008-like virus
The quadrivalent vaccine will contain those three along with B/Phuket/3073/2013-like virus. It is expected between 171 and 176 million doses of these vaccines will be available.

To get updated weekly influenza information during the flu season, visit the CDC’s website.


17. What about avian flu?
Get information about avian flu by accessing the following pages:

18. What about wearing a disposable N95 respirator?
Wearing a disposable, dust-mask style N95 respirator can help protect your against coming in contact with the influenza virus. But there are some things you should be aware of:
  • A disposable N95 respirator should be worn only by one person and properly discarded
  • It should only be worn once and thrown away in the trash; re-use of a disposable respirator can increase the risk of contact transmission of the virus by touching the contaminated surface of the respirator and then touching a mucus membrane of your face
  • If the disposable respirator comes in contact with contaminants (blood, respiratory or nasal secretions, or bodily fluids from other people), it should be disposed of immediately; it should also be discarded if it becomes damaged or if it is difficult to breathe through, even if the wearer is not done with it
  • Other classes of disposable respirators (N99 or N100, for example) can be considered because they are similar in design, shape and function to an N95

Back to Top