How Long am I Contagious with a Cold or Flu?

Janet Smith, CNP discusses cold and flu concerns. Click play to watch the video or read the transcript.


If you have a cold or the flu, you can be contagious even before you know you’re sick.

With the flu:

  • Adults can infect other people one day before symptoms appear and up to seven days after becoming sick, according to the Centers for Disease Control and Prevention (CDC).
  • Children can infect people up to four days before they have symptoms, and in total, can pass the virus to others for more than seven days, according to the CDC.

If you have a cold;

  • You’re usually contagious the day before you know you are sick.
  • You’re most likely to infect others in the first two to three days of having the cold.
  • You’re usually no longer contagious after a week.

Talk to your doctor for more information about how long cold and the flu can be contagious.

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