Why do we cough? A simple explanation for children

Everyone has had a cough at some time or another. But why do we cough? Where does the cough come from? Is coughing bad and should I do something to stop it? We explain simply and in a child-friendly way what a cough is, why we cough and answer frequently asked questions on the issue.

Reflexes are like superheroes that are there on the spot and respond if something happens – without you having to think about it. So, for example, if you accidentally burn yourself, you pull your hand away at lightning speed before your brain can say “Ouch”. Pulling your hand away is a reflex – a fast reaction of your body to something it wants to protect you from. Like a superhero who rescues you. So coughing is a reaction that protects your lungs.

Imagine your lungs are like two large, clean rooms in your body. Sometimes, unwelcome guests like dust, pollen, air pollution, breadcrumbs, a sip of water or enemies like cold viruses get into your lungs. Your body wants to get rid of these unwelcome visitors and it does that by coughing. The cough is like a strong blast of air that blows the unwelcome invaders out of your lungs.

There are things called “cough receptors” in your lungs. You can imagine them like tickle stops in your bronchial tubes. If dust, mucus, pollen or other invaders touch one of these cough receptors, it tickles the lungs and you have to cough.

But you can also imagine the cough receptors as an alarm system that goes off as soon as an intruder appears. When the alarm goes off, a superhero (= cough reflex) appears on the spot and gets rid of the villain.

There are many different things that make you need to cough. These are called “triggers”. We have listed some of them here.

You’re sure to have at some point swallowed water, a bit of bread or your own spit down the wrong way. The cough receptors at the entrance to your lungs sound the alarm because water, spit or breadcrumbs definitely should not be getting into your lungs. Coughing keeps them at bay.

Even really tiny particles in the air like dust, pollen or toxins (poisons) like the ones in cigarette and cigar smoke or like the ones in car exhaust fumes can tickle your cough receptors. That makes you cough too.

Unbelievable, but true: Snot from your nose can also make your lungs need to cough. Your lungs are connected to your nose through your throat and pharynx. If you have a really runny nose and there is lots of snot in your sinuses (spaces above your nose in your forehead and cheeks that connect to your nose), at some point this will drip down the back of your throat.

Your lungs are certainly not going to welcome snot from your nose. Who would? This is why the coughing reflex then leaps into action and the snot from your nose ends up in your mouth and not in your lungs. You can either swallow the snot into your tummy or spit it out into a tissue.

Having mucus in your lungs will also make you cough. This is because the mucus, which may have germs trapped in it, tickles the cough receptors. Your body wants to get rid of it because it is difficult for you to breathe if your bronchial tubes are full of mucus. This is why your lungs want to get it out.

There are chronic diseases (= that last a long time) where you produce too much mucus. This is why people with these diseases cough a lot. Examples of these diseases are: cystic fibrosis and primary ciliary dyskinesia. But allergies to pollen, dust, animal hairs and things like that or severe asthma can make your body react by producing too much mucus in the bronchial tubes, which can make you cough.

With asthma, there is the added problem that the mucous membranes in the bronchial tubes swell up and get so thick that they actually touch the cough receptors. That is like the lungs tickling themselves. That makes you cough too.

This is what happens in your body when you cough: You automatically breathe in deeper. Then all the muscles tense up as a reflex and that means your chest gets tighter. That builds up pressure. Then this pressure is suddenly released, and the air you breathed in shoots out of your lungs like an explosion. You cough. The blast of air is so strong that it takes the mucus, the dust and all the other stuff out with it.

And your muscles help you do this: The muscles in your belly, your back and your throat. If you have a really violent cough, even some of the muscles in your legs!

Generally, there’s nothing wrong with coughing because it does an important job to help your body protect itself. But when you cough, something should always be drawn up out of your lungs – like mucus, for example.

You should, however, avoid a dry cough. Because coughing is very strenuous. A dry cough means that you cough again and again without anything really coming up out of your lungs. The cough feels dry.

Also, coughing hard all the time is not good for your body. But you can learn to control a dry cough and to suppress it. If you would like to know how to do that, read our tips on how children can cough properly.

You should be considerate of other people and cough into the crook of your arm. This stops any germs spreading too far into the air. It also keeps your hands clean.

This article was written in cooperation with Marlies Zieger. She works as a physiotherapist in private practice in Munich. She specialises in respiratory therapy. She has been treating patients with chronic obstructive and restrictive airway diseases such as asthma, COPD, cystic fibrosis (CF) and primary ciliary dyskinesia (PCD), for more than 20 years.

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Note: The information in this blog post is not a treatment recommendation. The needs of patients vary greatly from person to person. The treatment approaches presented should be viewed only as examples. PARI recommends that patients always consult with their physician or physiotherapist first.