Here is a question you may have wondered about. What is snot? Snot is mucus, a sticky, slimy stuff that the nose makes, and clear, thin mucus is normal and healthy, because everybody makes it. It keeps the inside of the nose moist. Let's find out what it is made of, where it goes and what it does for you. It is a good place to start, and it is a fun one.

What is it made of? It is made of water, mucin proteins, defense proteins and salt. Mucin is the main part, and it gives it a gel-like feel. Who makes the mucin? Goblet cells make it, and they are shaped a bit like a fancy drinking glass. That is a long list, so take it one part at a time.

Have you ever wondered what is going on inside your nose? Airway mucus has two main layers. On top is a sticky gel layer. Underneath is a watery layer that surrounds the cilia and lets them beat. Next, let's meet the cilia and see what they do.

Cilia are tiny hair-like strands in the nose that wave back and forth all the time. They line the airways and push mucus along, like an escalator. Cilia sweep it, with the stuff it has caught, toward the throat. You may have heard that swallowed mucus will hurt your stomach. In fact, when we swallow it, it meets stomach acid, which helps destroy the harmful material in it.

Think about the air around you right now. Sometimes viruses and bacteria float in the air we breathe, and the nose traps many of them. Hairs inside the nostrils help block bigger bits of dirt from getting into the nose, and mucus-covered hairs help trap larger particles as they enter the nose. So what does the nose do about all of that?

Mucus lines the inside of the nose, and it also lines the lungs and the digestive tract. As of November 2026, the nose and sinuses make about a quart, or about 1 liter, every day, but experts say nobody knows the exact amount. That is a lot to keep track of, and the body does it for you. Let's see how that goes.

Now, what is a booger? A booger is dried mucus mixed with bits of dust, pollen and dirt. Blowing your nose into a tissue is a good way to clear out boogers, and a tissue traps germs. Picking the nose can make it bleed, and boogers contain lots of germs, so a tissue is a better tool. Now you know what to do with one, and that is worth remembering.

What happens when you are sick? A runny or blocked nose is a main sign of a cold, and a cold usually gets better on its own in about one to two weeks. Hay fever is an allergy to pollen, the fine powder plants make, and it can bring sneezing and a runny nose. The color of snot alone does not tell you what is going on inside the body.

How do colds spread? Colds are spread by germs from coughs and sneezes, which can land on hands and surfaces, and washing hands helps stop respiratory infections from spreading. Washing your hands with soap and water helps you stay healthy. Washing with soap for about 20 seconds is a good length, and you can count it out in your head.

Let's put it all together. Mucus holds antibodies, which are proteins that help the body find germs. Almost all the dust and germs we breathe in get trapped in mucus, and the cilia carry it toward the throat. Mucus in the nose catches dust and germs so they stay out of the lungs, and it also protects the lungs, because it acts like a shield against germs.

Words to know

• mucin: gel protein
• cilia: tiny sweeping hairs
• antibodies: germ finders
• goblet: fancy glass
• pollen: plant powder