# Colds: How long infectious?

**URL:** <https://boards.straightdope.com/t/colds-how-long-infectious/521257>\
**Category:** Factual Questions\
**Created:** [December 14, 2009, 7:48pm UTC](https://boards.straightdope.com/t/colds-how-long-infectious/521257 "2009-12-14T19:48:46Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\
**Post date:** [December 14, 2009, 7:48pm UTC](https://boards.straightdope.com/t/colds-how-long-infectious/521257/1 "2009-12-14T19:48:46Z")

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Generally speaking, when does a person with a cold become non-infectious?

For example. Let’s assume a seven-day illness. The first day, the person starts to display symptoms. The third day symptoms reach their peak. Symptoms decline for the next few days. When is it safe to be around other people? _X_ days after symptoms start to decline? The day symptoms disappear? _X_ days after symptoms disappear?

Full disclosure: Yes, I have a cold. But this is a general question about colds, and not specific to me. Just something I’ve always wondered.

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**Author:** ![pan1](https://avatars.discourse-cdn.com/v4/letter/p/e495f1/32.png) [@pan1](https://boards.straightdope.com/u/pan1)\
**Post date:** [December 14, 2009, 8:00pm UTC](https://boards.straightdope.com/t/colds-how-long-infectious/521257/2 "2009-12-14T20:00:47Z")

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When you aren’t sneezing or coughing it around (without meds), you’re no longer contagious.

Basically you are contagious for as long as you have a runny nose. When that stops it’s an indication that the virus is no longer present and the sneezing stops. Coughing is usually a secondary symptom - from snot running down into the throat from the nasal passages.

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**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\
**Post date:** [December 14, 2009, 8:55pm UTC](https://boards.straightdope.com/t/colds-how-long-infectious/521257/3 "2009-12-14T20:55:31Z")

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Although I might not agree entirely with him, [here’s](http://www.straightdope.com/columns/read/1438/how-long-are-colds-contagious) what Cecil says.

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**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\
**Post date:** [December 14, 2009, 9:15pm UTC](https://boards.straightdope.com/t/colds-how-long-infectious/521257/4 "2009-12-14T21:15:34Z")

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> [@KarlGauss](#):
>
> Although I might not agree entirely with him, [here’s](http://www.straightdope.com/columns/read/1438/how-long-are-colds-contagious) what Cecil says.

Thanks for that.

If anyone is curious, but does not want to read the column:

> [@](#):
>
> To answer your question, the common cold is “contagious” between 24 hours before onset of symptoms until 5 days after onset. Like everything else this varies depending on the organism, but that’s a pretty safe estimate.

And yes, I’ve been telecommuting since the onset of symptoms. 😉