Where does all the snot come from?

January 21, 2012 - 05:00

How can humans produce so much phlegm or mucous?

A runny nose is a sure symptom of a cold, but also allergies can turn your nose into a leaking faucet. (Photo: Colourbox)

Winter has come to the Northern part of the world, and people are suffering from colds. 

One symptom of the seasonal cold is the runny nose. There seems to be no end to the fluid flowing out of the nose and the pile of used paper tissues are growing bigger by the hour.

How is it possible for a person to produce so much snot? We decided to consult science.

Niels Christian Stenklev is an associate professor at the University of Tromsø and a specialist in otalaryngology, in other words, an ear, nose and throat doctor. He should know enough about snot.

“When we catch a cold we are usually infected by a virus. It takes about two days from being infected until you start to feel the symptoms.”

“The virus has spent this time migrating into the mucous membrane cells of your nose, multiplied itself and created an inflammation reaction in the mucous membranes,” explains Stenklev.

Inflammations are actually one of the body’s protective mechanisms against foreign organisms and material.

“As a part of this process a number of signal substances are released the mucous membranes of your nose. These lead to increased production of mucous, more blood is channelled to these membranes and more body water is leaked out between the cells of the mucous membranes,” says Stenklev.

We experience this as having a stuffy nose and a lot more snot runs out than usual.

Mucous plus a little more

Snot is actually a collective designation for everything that comes out of your nose, with the exception of when you have a nosebleed.

When you are healthy it runs out as mucous. If the mucous is dried you get boogers. When you catch a cold the production increases and the phlegm and body water run from your nose.

If you have a bacterial infection you get also get pus – which is a mixture of dead tissue, bacteria and white blood cells, or leukocytes.

The colour of snot can tell us show sick we are:

Clear and colourless snot is okay, yellow or green indicates a viral or bacterial infection. Your body is sending leukocytes to the mucous membranes in your sinuses to fight the infection, and the aftermath of this battle gives your snot colour.

Snot and culture

There are all kinds of myths and taboos linked to our bodily fluids. Blood, for instance, plays a big role in religions. It can stand for vitality, purgation, forgiveness and healing. Blood can be warm or cold. It was also one of the “four humours” of the Greeks, the others being black and yellow bile, and the subject here − phlegm.

In ancient times it was believed that bad-tempered people had too much yellow bile and melancholy ones had an excess of black bile. Snot also enters the picture, as too much phlegm makes a person phlegmatic – gives them an unemotional or stolid disposition.

Of course tears play a heavy role in literature, film and art, and they have a palliative effect and can easily infect a sympathetic audience. 

But snot is never praised by artists or priests.

It’s simply gross.

That’s overlooking the fact that it’s very essential, whether we’re sick or not. Snot is a kind of garbage removal.

Our nasal hairs catch bacteria, viruses, grains of dust and pollen and other unwanted foreign elements, so that they don’t easily follow the air into our lungs. Snot transports it out again through the nose or down into your stomach.

Problematic snot

Most of us consider it enough just managing our own snot. But some are concerned about others’ yucky substances.

In a research project about smell, fluids and shame the sociologist Lise Widding Isaksen at the University of Bergen studied health and care workers’ relationship to various body fluids.

Breast milk was viewed as the cleanest and most acceptable body fluid. Snot was much more difficult, ranking along with blood and vomit near the bottom of the list, only surpassed by excrement.

Beautiful and healthy?

Blood can be beautiful, excrement can provide relief for the person involved, and for some people urine is sexy. But phlegm is never coveted. At best it’s a sign of a peak performance and effort when it’s frozen onto the face of cross-country skier who’s first across the goal line.

But doctors say it can also be healthy. Also if we eat it! When we do so, we consume bacteria that can actually protect our bodies from bacterial attacks.

There’s even a facebook group that views it as a source of nourishment: “Eating Snot is NOT Disgusting! It’s a Good Source of Glycolsilated Protein”.

Apparently, medical textbooks don’t have a pat answer regarding how much snot a person can produce. Some produce more than others, that’s normal.

And it isn’t your brains leaking!

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Translated by
Glenn Ostling

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