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Speaker 1: Welcome to brain Stuff from how Stuffworks dot Com where

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Speaker 1: smart Happens him Marshall Brain. When someone says I have

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Speaker 1: a cold, what does he mean? What he means is

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Speaker 1: there's something inside my body that's causing me to have

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Speaker 1: a set of symptoms that we call a cold. The

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Speaker 1: set of symptoms normally includes things like a running nose, sneezing, coughing,

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Speaker 1: sometimes chills, and a headache. It doesn't include a fever. Normally,

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Speaker 1: if there's a fever, we call it the flu. There

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Speaker 1: are many different viruses that can cause cold symptoms, but

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Speaker 1: about half the time the cold is caused by a

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Speaker 1: class of virus is called rhinoviruses. The rhinovirus gets into

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Speaker 1: the cells lining your nose and it starts reproducing. It

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Speaker 1: arrives from other people. It's not cold weather that causes

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Speaker 1: a cold, but the fact that cold weather causes people

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Speaker 1: to congregate together indoors, and that makes transmission of the

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Speaker 1: virus easier. The virus generally moves from someone else's hands

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Speaker 1: to your hands through something like a door knob, and

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Speaker 1: from your hands into your nose or eyes. Your body

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Speaker 1: reacts to the presence of the rhinovirus with its immune system.

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Speaker 1: In the case of a cold, the immune system opens

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Speaker 1: up blood vessels inside your nose through inflammation, and it

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Speaker 1: also increases mucus. These two processes give you the running

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Speaker 1: nose and the stuffy feeling. The irritation caused by the

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Speaker 1: virus and all the fluid causes sneezing. If the virus

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Speaker 1: makes it into the cells lining the lungs, then they

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Speaker 1: start producing fluid and mucus as well, and that produces

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Speaker 1: the cough. As the immune system gears up over several

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Speaker 1: days and fights the virus, the mucous thickens and it

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Speaker 1: changes color with dead cells a form of pus really yuck.

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Speaker 1: And event actually the immune system eliminates the virus completely

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Speaker 1: and your well again. The whole healing process takes seven

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Speaker 1: to ten days. Do you have any ideas or suggestions

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Speaker 1: for this podcast? If so, please send me an email

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Speaker 1: at podcast at how stuff works dot com. For more

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Speaker 1: on this and thousands of other topics, go to how

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Speaker 1: stuff works dot com and be sure to check out

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Speaker 1: the brain stuff blog on the how stuff works dot

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Speaker 1: com home page.