Common Questions About Coughs

Coughs are one of the most common reasons parents bring their kids to the doctor; they can sound scary, and they seem to last forever. But the truth is, most coughs are a totally normal part of the body’s defense system.

As a pediatrician, when I see a child with a cough, I always approach it by trying to figure out if this is a standard cold or something that needs a different approach. I’ll want to know how long the cough has lasted, whether there’s been a fever, if the child is still playful between coughs, and whether anyone else at home is sick. I’ll also think about the child’s medical history. All of these details help me sort out whether this is a standard viral cough or if I need to worry about something more unusual.

Below are some common questions I hear from parents about coughs to hopefully guide your decision-making. But as always, when in doubt, call your pediatrician.

Take me to the bottom line

What causes a cough?

A cough is a reflex designed to keep the airway clear. Sensory nerves in the throat and chest, mostly carried by the vagus nerve, detect irritation and send a signal to the brainstem. The brain has its own little “cough center,” which launches the sequence: a deep breath in, the voice box closes, the chest and belly muscles squeeze, and then a burst of air rushes out.

That irritation can come from many sources, but almost all coughs in kids are caused by short-lived viral infections. Less commonly, a cough can be triggered by bacterial infections, asthma or reactive airways, allergies, or (especially in toddlers) a foreign body that a child aspirated into their airway (meaning, they swallowed something).

When should you worry about your child’s cough?

The main things to watch are your child’s work of breathing and their activity level when they aren’t coughing. If they’re struggling to catch their breath, breathing very fast or very deeply, or if you notice color changes around the lips or face, they need to be seen right away.

Even with coughs, kids should have moments of playfulness. If your child is unusually tired, hard to wake, or lying around with no energy, that’s a concern. High or persistent fever, coughing fits that leave them breathless, and any sudden, constant cough that starts after choking are also signs that warrant a call to your pediatrician. Coughs in babies under 3 months are always taken seriously. And if a wet cough lingers beyond four weeks, it’s worth being checked out.

Why does it feel like my kid always has a cough?

Once kids are in day care or preschool, they pick up a lot of viruses. Adults get about two or three colds a year, but infants and preschoolers average 7 to 10 respiratory infections annually. Symptoms often last 10 to 14 days, which means it is completely normal for a young child to be coughing more than a third of the year.

And this isn’t evenly spread out. Between November and May, children may feel sick more often than they feel well. The good news is that as they get older, the number of infections drops, and by high school, their pattern looks a lot more like adults.

How long is too long for a cough to linger?

Coughs often hang on after the rest of an illness has cleared. This can be from post-nasal drip, where mucus trickles down the back of the throat and keeps triggering the reflex, especially at night or in the morning. Another reason is that the irritation from the virus makes the airway nerves a little twitchy for a while. We sometimes call this “post-viral airway hypersensitivity,” but really it just means the throat overreacts to small triggers until it calms down.

About half of the coughs are gone by 10 days, and about 90 percent by three to four weeks. That four-week mark is the point many pediatric guidelines use to define a chronic cough, and it’s a good time to check in with your pediatrician. Often, we find that what seems like one long cough is actually one virus stacked on another. But at that stage, it’s also important to think about other possibilities (asthma, a bacterial infection, or a foreign body). Your pediatrician can help you sort through these possible options.

Does it matter what a cough sounds like?

There are three main ways a cough can sound: barking, dry, or wet. A barking cough often comes from croup, which matters because it responds to treatments that colds don’t. The difference between wet and dry is less important. A wet cough usually means mucus is present, and a dry cough comes more from airway irritation. Both, though, are most often caused by viruses, so the sound helps us think about the possibilities but usually doesn’t change how we treat it.

What is croup?

Croup is one of those illnesses that looks and sounds a little different from the usual cough. It is most often caused by parainfluenza, but almost any respiratory virus can cause it, including the common cold viruses, influenza, RSV, and COVID. What makes croup distinct is not the virus itself but where the inflammation happens. When a virus irritates the voice box (larynx) and windpipe (trachea), the swelling narrows those passages. Because children’s airways are small to begin with, even a little swelling makes it harder for air to move through. That is what creates the classic seal-like, barky cough and, in more severe cases, the high-pitched whistling sound called stridor when a child breathes in. Stridor is a warning sign that the airway is tight and the child is working harder to breathe.

The good news is that croup usually responds well to treatment. For mild cases, parents are often told to try cool night air or bathroom steam. Hospital studies have not shown these to reliably improve symptoms, although one recent trial did find that spending time in cold outdoor air helped some children. Regardless, these approaches have little downside and may make children more comfortable.

When symptoms are more severe, especially if there is stridor or obvious trouble breathing, medical treatments are very effective. Steroids calm the airway swelling, and inhaled epinephrine can quickly open the airway while the steroid takes effect.

Croup tends to last about three nights and usually peaks on the second or third. If the first night is rough, it is a good idea to see your pediatrician the next morning, even if your child seems better in daylight. Starting steroids early can make the next night safer and easier. After those first few days, the illness usually settles into symptoms that look more like a standard cold.

Why are coughs worse at night?

Part of the reason is perception: it’s much more memorable to be woken by a cough than to hear it during the day. But it’s not all perception — coughs really are worse at night. There are two main reasons. First, when kids lie down, mucus that would otherwise drain out of the nose runs down the back of the throat, where it irritates the cough reflex. Second, cortisol — our body’s natural anti-inflammatory steroid — is lowest at night. With less of this natural protection, the airway swells a little more, and mucus builds up more quickly, making coughs more frequent after bedtime.

Can allergies cause coughing?

Yes, and in more than one way. Some children have allergic rhinitis, which means that when they’re exposed to an allergen, they get a runny nose. The mucus that drips down the back of the throat can trigger coughing. In other children, allergens can set off asthma symptoms, which also show up as coughing. It isn’t always easy to tell allergies from infection, but itchy eyes or wheezing are more common in allergy-related coughs. Sometimes, we trial allergy (such as Zyrtec or Claritin) or asthma (albuterol) medications, and if the cough improves, that helps make the diagnosis.

What if my child coughs until they vomit?

This is not unusual. Kids have sensitive gag reflexes, and a strong cough can trigger vomiting. If it happens once in a while, it usually isn’t worrisome. If it’s happening often or with coughing fits that leave them breathless, then pertussis, or whooping cough, becomes a concern.

How can you treat a cough in young children?

The short answer is that there isn’t a medicine that reliably makes a viral cough go away. Over-the-counter cough and cold medications have been studied, and they don’t work in children. More importantly, they can cause side effects and even harm, which is why in 2007, the FDA warned against their use in children under 2. In 2011, the American Academy of Pediatrics extended that recommendation, saying they should not be used under age 6 and are discouraged up through age 12.

There is one exception, and that’s honey. Several randomized controlled trials have shown that for children over a year old, honey can improve nighttime cough and help both kids and parents sleep better. For children under 1, honey generally isn’t recommended because of the risk of infant botulism.

Other common treatments like humidifiers, steam, or warm fluids are widely used and generally safe, but the studies we have don’t show clear evidence that they make coughs resolve more quickly. They may help comfort, and that’s important, but the main healer for a cough is time.

Can you prevent coughs?

There are some coughs we can prevent. Vaccines protect against infections like whooping cough, pneumococcus, and Hib, and the flu and COVID vaccines cut down on the likelihood of those viral infections, too. But for the majority of colds — the ones that cause most coughs — we don’t (yet!) have vaccines.

Handwashing, masks, and avoiding crowds during viral season can all reduce your child’s risk. How much you lean into those strategies depends on your own comfort and risk tolerance. Some families are willing to accept more frequent colds in exchange for fewer restrictions; others want to reduce exposure as much as possible. Both approaches can be reasonable. Even with precautions, though, coughs are still very much a part of childhood.

The bottom line

Most coughs are from viruses and clear on their own.
Watch your child’s breathing and energy, know the red flags for when to go to the pediatrician, and focus on comfort while you wait for the cough to run its course.