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Facts About the Flu

What is influenza?
The flu is an illness that affects the nose, throat and lungs. It is caused by a flu virus. The flu affects people every fall and winter – that's why the time of year from November to April is known as "flu season." The flu can cause mild illness or it can be serious. In certain people, it can cause severe illness, lead to hospital care or cause death.

There are three types of flu viruses: A, B and C. The A and B types can cause epidemics (widespread outbreaks of flu). No C flu viruses have been known to cause epidemics.

Flu viruses change from year to year, so that is usually why a new flu vaccine needs to be made each year.

How do I know if I have the flu?

People who have the flu can have a variety of symptoms, but most of all, they feel pretty terrible.
Other things to look for include:

  • Fever
  • Coughing
  • Sore throat
  • Runny or stuffy nose
  • Headaches
  • Body aches
  • Chills
  • Fatigue (feeeling tired)

If you do have the flu, learn what you can do about it.

Who can get the flu?
The flu can affect people of any age. Children, the elderly and people who have other health conditions (like diabetes, asthma, congestive heart failure and lung disease) are more likely to get sicker because their immune systems aren't strong enough to fight off the infection.

How does the flu spread?
Flu germs can spread through the air when a person with the flu coughs or sneezes. People who breathe those germs in can get sick.

Also, if a person with the flu coughs or sneezes on their hands and then touches something (like a doorknob, desk or handrail), they can put flu germs on that thing. If someone else then touches that thing and then touches their face, they can get sick from the flu.  

How can I keep from getting the flu?

Get a flu shot. The best way to keep from getting the flu is by getting a flu shot every year. Plus, getting vaccinated not only protects you, it also helps keep your family from catching the flu! If you don't get the flu, you can't spread the flu! Everyone who is six months old or older should get their flu shot every year. Learn more about the flu shot. You can see the schedule for all PDPH-sponsored flu shot clinics here.

There are other steps you can take every day to protect your health, too:

  • Cover your cough. Cover your nose and mouth with a tissue when you cough or sneeze, then throw away the tissue and wash your hands.
  • Wash your hands often. Use soap and water or an alcohol-based hand sanitizer. Wash every time you eat, handle food, use the bathroom, change a diaper, touch a wound, blood or body fluids, and when they look dirty.
  • Stay home when you are sick. If you are sick, stay home from work, school and running errands (unless you need to seek medical care). Stay home until at least 24 hours after you no longer have a fever (100°F).Avoid close contact with others. This will help keep others from catching your illness.


Learn more about stopping the spread of germs.

Is the flu serious?
It is a myth that the flu is “no big deal.”  In fact, each year in the United States, on average:

  • 5 to 20% of people get the flu.  
  • More than 200,000 people are hospitalized from flu-related complications.
  • About 36,000 people die from flu-related causes.

What is the difference between a cold and the flu?
The flu and the common cold are both respiratory illnesses, but different viruses cause them.  They have similar symptoms (such as fever and sore throat), so sometimes it is hard to tell the difference. Here are some differences:

The Common Cold

The Flu

  • Usually mild illness.
  • Usually does not result in serious health problems, such as pneumonia, bacterial infections, or hospitalizations.
  • More likely to cause runny or stuffy nose.
  • In general, the flu is worse than the common cold.
  • Symptoms such as fever, body aches, extreme tiredness and dry cough are more common and more intense.
  • A doctor can give you a flu test within the first few days of illness to see whether you have the flu.


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