Welcome to brain Stuff from how Stuffworks dot Com where smart Happens him Marshall Brain. When someone says I have a cold, what does he mean? What he means is there's something inside my body that's causing me to have a set of symptoms that we call a cold. The set of symptoms normally includes things like a running nose, sneezing, coughing, sometimes chills, and a headache. It doesn't include a fever. Normally,
if there's a fever, we call it the flu. There are many different viruses that can cause cold symptoms, but about half the time the cold is caused by a class of virus is called rhinoviruses. The rhinovirus gets into the cells lining your nose and it starts reproducing. It arrives from other people. It's not cold weather that causes a cold, but the fact that cold weather causes people to congregate together indoors, and that makes transmission of the
virus easier. The virus generally moves from someone else's hands to your hands through something like a door knob, and from your hands into your nose or eyes. Your body reacts to the presence of the rhinovirus with its immune system. In the case of a cold, the immune system opens up blood vessels inside your nose through inflammation, and it also increases mucus. These two processes give you the running nose and the stuffy feeling. The irritation caused by the
virus and all the fluid causes sneezing. If the virus makes it into the cells lining the lungs, then they start producing fluid and mucus as well, and that produces the cough. As the immune system gears up over several days and fights the virus, the mucous thickens and it changes color with dead cells a form of pus really yuck. And event actually the immune system eliminates the virus completely and your well again. The whole healing process takes seven
to ten days. Do you have any ideas or suggestions for this podcast? If so, please send me an email at podcast at how stuff works dot com. For more on this and thousands of other topics, go to how stuff works dot com and be sure to check out the brain stuff blog on the how stuff works dot com home page.