As of the August 2010 pandemic, H1N1 flu is no longer considered a pandemic. This fact sheet provides historical information about pandemic H1N1 flu and will no longer be updated. Please see the Centers for Disease Control and Prevention website at for the latest information about H1N1 flu.

Pandemic H1N1 flu (originally called swine flu) is a respiratory infection. The pandemic H1N1 flu has spread to humans and has reached the level of a pandemic. A pandemic is a worldwide outbreak.

The main risk factor for getting the pandemic H1N1 flu is contact with an infected person. People with the flu can infect others through coughing and sneezing. You can also get the flu by touching an infected object. A chronic health condition such as heart or lung disease, diabetes, or cancer may increase your risk of a more severe form of the flu.

Symptoms may include:

  • Fever and chills
  • Sore throat
  • Cough
  • Severe muscle aches
  • Severe fatigue
  • Headache
  • Runny nose, nasal congestion
  • Sneezing
  • Watery eyes
  • Stomach symptoms like nausea, vomiting, and diarrhea

Most people recover at home. Basic care includes rest, fluids, and over-the-counter pain relievers. Antiviral medications may be used. They may be given to prevent or treat an H1N1 infection.