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H1N1 (Swine) Flu

What Is H1N1?

Last year, "swine flu" was all over the news. This strain of flu virus (a combination of flu viruses that affect pigs, birds, and humans) first surfaced in spring 2009. Later that year, health experts declared an H1N1 "pandemic," meaning the new virus had spread widely around the world and there was a risk a lot of people could become seriously ill.

In the end, the H1N1 pandemic turned out to be far less serious than previous flu pandemics. H1N1 influenza is still around, but it's less of a health concern than it once was. So what's the story with H1N1?

How Do People Get It?

H1N1 spreads the same way as other flu viruses do — through the air when a person who has the virus sneezes, coughs, or speaks. People also can catch the virus after touching an object that someone with the virus sneezed or coughed on.

As with other flu viruses, people who have H1N1 can be contagious a day or so before their symptoms start. So they can pass it on before they even know they're sick.

What Are the Signs and Symptoms?

Symptoms of H1N1 flu are similar to other flu symptoms. A person may notice:

  • fever
  • cough
  • sore throat
  • runny nose
  • body aches
  • headaches
  • tiredness

Some people also might have diarrhea or vomiting.

How Can I Protect Myself?

The Centers for Disease Control and Prevention (CDC) recommends that people take the following precautions against any type of flu:

  • Wash your hands often with soap and water or use hand sanitizer — particularly before eating.
  • Avoid touching your eyes and mouth.
  • Avoid being around people who are sick and be sure to wash your hands if you touch anything someone who seems sick might have touched.
  • Get a flu shot. This season's flu vaccination requires only one shot for most people.
Reviewed by: Kate M. Cronan, MD
Date reviewed: October 2010