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I’m sitting here with a cold, which means I’m getting that skanky feeling of dehydration when every cubic centimeter of water one consumes is allocated toward snot production. Aside from making me have to cough and blow my nose a lot, it leads me to wonder about the physiology of mucus. Does the body actually use it for something, or is it simply a by-product of some other process? How is it that as soon as I blow it all out, my nose and sinuses seem to fill right back up in less than a second? How does the body produce so much of it so fast? Have any yogis with superior body-wisdom found a way to retain in the body valuable water that might otherwise go to producing worthless snot? Or would that be counterproductive to the healing process?

–Yours ob’tly, Keith Ammann, Albany, New York

This will pretty much complete our series on the lesser bodily secretions, unless somebody really wants to go into the smegma thing. As is true of all God’s creation, mucus is good for you. No doubt you could stand to have a little less of it at times, but this shouldn’t decrease our esteem for a fluid that’s only trying to defend us against germs, dust, and other foreign matter. Evidently, since you got a cold, this defense against germs wasn’t entirely successful. But the mucus is trying! You might show a little appreciation.

Under normal circumstances–that is, when you don’t have a cold–nasal mucus is part of the system by which your body conditions “inspired air” (the term medical writers use for inhaled air; I could just say “inhaled,” but as a writer I prefer to think that the very air I breathe is inspired). The air swirls through your nasal passages and gets warmed up. Meanwhile the dust and other bad stuff strikes the mucus-lined sides and sticks. Or rather, it strikes the mucus-lined ciliated epithelium of the posterior nasopharynx and…well, I guess “sticks” is not the word you want to use in this context. Adheres, maybe. Anyway, the cilia (little hairs) and mucus then transport the debris to the rear of the mouth, whence you can hawk it up. This is called postnasal drip. Another of life’s little annoyances that you ought to be grateful for.

As I say, the above mechanism is not a foolproof antimicrobial defense, and sometimes you get a cold. Feeling guilty, your mucus then kicks into overdrive trying to shed this virus or whatever bad thing it is you’ve got. Sometimes it succeeds, at least to the point where you can continue to breathe through your nose. Sometimes it doesn’t and your nose plugs up, and the infection takes root in your sinuses, producing the dreaded green globs and making you sound like your head was whittled from a potato. You think this is better than having a runny nose? I think not. Sorry if I sound like I’m dumping on you, Keith, but I’m trying to put matters in perspective. Your problem isn’t the mucus, it’s the germs.

The reason you have a seemingly inexhaustible supply of mucus when suffering from a cold is that the mucus-producing cells lining your nasal cavity extract the stuff from your blood, which transports the raw materials (mostly water) from other parts of the body. Water from your blood diffuses through the capillary walls and into the cells, and moments later it winds up in your snot-rag. Blood is the highway for all (well, most) of your bodily fluids, including saliva and perspiration. When somebody says he’s sweating blood, he’s not exaggerating. Incidentally, you probably produce less mucus than you think. Experiments show that on the peak day of a cold the average person produces about 14 grams of drippings, or roughly half an ounce.

Another question I’m asked from time to time is, what’s the chemical formula for snot? (Don’t bitch about the stuff you get in the mail.) I have no definite answer to this. Ninety-five percent of mucus is H2O, while the remainder is protein, carbohydrate, lipids, and miscellaneous, the proportions and nature of which vary. I found some discussion about what makes mucus, um, stringy, but I figured this was something you’d just as soon not know.

Finally, I came across an article entitled “Effects of Drinking…Chicken Soup on Nasal Mucus Velocity.” Says the “Jewish penicillin” (authors’ term) is indeed salubrious, but only for half an hour, largely because the healing vapors penetrate the nose and loosen things up. So eat your chicken soup already, because science has proved that mama knows.

Art accompanying story in printed newspaper (not available in this archive): Illustration by Slug Signorino.