RSV, Croup or Bronchiolitis? How to Tell What’s Behind the Cough Sounds
, by Tatianna Gerard, 15 min reading time
If you’ve ever been woken in the middle of the night by the sound of your child coughing, you’ll know how quickly concern can creep in. Is it just a cold? Are they struggling to breathe? Do you wait and see — or call the doctor?
Coughs are one of the most common symptoms in young children, especially during the colder months or peak virus season. Some can be dry and barking, others wet and wheezy — and the type of cough your child has can offer important clues about what’s going on in their airways.
Infections like RSV (respiratory syncytial virus), croup, and bronchiolitis often start off looking similar — a runny nose, a low fever, a child who’s not quite themselves. But as the illness progresses, each one tends to take a different path, especially when it comes to how the cough sounds and how the breathing is affected.
What is RSV
RSV — short for respiratory syncytial virus — is a very common virus that infects the respiratory system. By the age of two, most children have had RSV at least once, and for many, it causes nothing more than a runny nose and mild cough.
But RSV is also the leading cause of more serious respiratory infections in infants and toddlers, particularly croup and bronchiolitis — which is why it’s important for parents to understand what it is and how it works.
The tricky thing about RSV is that while it starts off like a regular cold, it can move further into the respiratory tract and affect different parts of the airway depending on the child’s age, health, and individual response.
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When RSV causes croup, it affects the upper airway — particularly the voice box (larynx) and windpipe (trachea) — leading to that harsh, barking cough and noisy breathing.
- When it leads to bronchiolitis, it settles into the lower airway — the small breathing tubes in the lungs called bronchioles — causing wheezing, chesty coughs, and fast or laboured breathing.
So, while RSV is the virus behind both conditions, the way it presents can vary significantly, which is why understanding the type of cough (and the part of the airway it comes from) can help guide how you respond.
For a deeper look into how RSV spreads, the symptoms to look for, and how to protect your child, check out our full article: What is RSV: Symptoms, Risks, Treatment, and Prevention.
RSV vs croup vs bronchiolitis
While RSV is the virus behind many childhood respiratory illnesses, the way it affects your child — and the type of cough that comes with it — depends on which part of the airway is involved. Here’s how to tell the difference between RSV infection, croup, and bronchiolitis, so you can better understand what your child’s symptoms might mean.
RSV infection
Cough: Persistent, often wet or mucousy.
Common symptoms:
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Runny nose
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Low-grade fever
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Wheezing
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Poor feeding
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Irritability
- Trouble sleeping
Who it affects:
Children of all ages, but especially infants and toddlers
What to know:
RSV often begins with mild cold symptoms, but in some children it can progress and cause more serious complications, depending on where the virus settles in the respiratory system. The general RSV cough may start out sounding like a normal cold before developing into something more.
Croup
Cough: Barking cough — often described as sounding like a seal. (Tends to be worse at night)
Common symptoms:
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Hoarseness
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Noisy breathing (known as stridor, especially when inhaling)
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Mild fever
- Symptoms often worsen at night
Who it affects:
Typically children aged 6 months to 3 years
What to know:
Croup affects the upper airway and can sound quite alarming, but many cases can be managed at home with calm reassurance, hydration, and sometimes a cool-mist humidifier. However, stridor that occurs at rest, breathing difficulty, or signs of distress may need urgent medical attention.
Bronchiolitis
Cough: Wet, chesty, may include wheezing or crackling sounds.
Common symptoms:
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Rapid or laboured breathing
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Flaring nostrils
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Difficulty feeding
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Tiredness or lethargy
- Occasional fever
Who it affects:
Mostly babies under 12 months, especially under 6 months
What to know:
Bronchiolitis happens when RSV (or sometimes other viruses) infects the smallest airways in the lungs (bronchioles), causing inflammation and congestion. Young babies have tiny airways, so even a small amount of swelling or mucus can make breathing much harder. Close monitoring is essential, and in some cases, babies may need hospital support for oxygen or fluids.
In summary:
| Condition | Type of Cough | Typical Age Group | Other Key Symptoms | When to Be Concerned |
| RSV | Wet, mucousy, persistent | Infants & toddlers | Runny nose, wheezing, poor feeding, irritability | Breathing difficulty, lethargy, poor feeding |
| Croup | Harsh, barking (seal-like), worse at night | 6 months to 3 years | Hoarseness, stridor, mild fever | Stridor at rest, breathing difficulty, signs of distress |
| Bronchiolitis | Chesty, crackly, wheezing | Under 12 months | Fast breathing, flaring nostrils, tiredness | Trouble feeding, blue lips, severe breathing effort |
Signs your child may need a doctor’s care
It’s completely normal to feel unsure when your child is unwell — especially when a cough lingers or their breathing doesn’t sound quite right. The truth is, many cases of RSV, croup, and bronchiolitis can be managed safely at home with rest, fluids, and close monitoring. But there are times when medical care is not just helpful — it’s essential.
Here’s how to recognise when it’s time to get help.
Warning signs to watch for:
1. Breathing difficulty
- Chest sucking in with each breath
- Fast or laboured breathing
- Tummy visibly working hard to breathe
2. Noisy breathing or pauses in breathing
- Wheezing or stridor that doesn’t improve with rest
- Long pauses between breaths or very shallow breathing
3. Blue or pale colouring (Especially around the lips, tongue, or fingertips)
4. Poor feeding or signs of dehydration
- Refusing feeds or bottle
- Fewer wet nappies than usual (dry for 6 hours or more)
5. Lethargy or sudden tiredness (Unusually drowsy, floppy, or difficult to wake)
6. High fever or sudden worsening (Particularly if it lasts more than a few days, or comes on rapidly)
Trust your instincts
You know your child best. If something feels off — even if their symptoms don’t “tick every box” — it’s okay to call your GP, nurse hotline, or go to urgent care. You don’t need permission to be cautious, especially when it comes to breathing or changes in behaviour.
If your child is under six months or has a pre-existing condition (like asthma, prematurity, or heart issues), it’s worth being extra vigilant.
How to care for a sick child at home
If your child is unwell but doesn’t need to see a doctor, home is often the best place for rest, recovery, and comfort. Whether they’re dealing with RSV, croup, or bronchiolitis, most mild cases will improve with time, care, and a little extra attention to their breathing, hydration, and rest.
1. Keep them well hydrated
Small, frequent sips of water, breastmilk, or formula are ideal — even if your child doesn’t feel like eating much. Dehydration can creep in quickly, especially if they have a fever or are breathing fast. For older children, clear fluids like warm soup or electrolyte ice blocks may be soothing and hydrating.
2. Use a humidifier or vapouriser
A cool-mist humidifier can help loosen mucus and make breathing easier — especially helpful for croup, when the airways are irritated and dry. Place it near your child’s bed during sleep, but always follow safety instructions and clean it regularly to prevent bacteria build-up.
3. Clear blocked noses gently
Nasal congestion can make feeding and sleeping difficult — especially for babies. You can:
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Use saline nasal sprays or drops to loosen mucus
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Follow with gentle suction using a bulb syringe or nasal aspirator
- Repeat before feeds and naps to keep airways clearer
4. Encourage rest and comfort
Let your child rest in whatever position feels easiest for them. Some babies breathe better when slightly elevated (in your arms or on a slight incline during supervised rest). Keep the room calm and quiet, and offer lots of cuddles and reassurance.
5. For kids aged 3 and up: Consider AirPhysio for mucus clearance
If your child is over 3 years old and experiencing ongoing chest congestion or trouble clearing mucus after an illness like bronchiolitis, the AirPhysio Children’s Mucus Clearance Device is a helpful, drug-free tool to support recovery.
This gentle, handheld device uses OPEP (Oscillating Positive Expiratory Pressure) — a natural method that helps loosen mucus in the lungs. As your child breathes out into the device, a small, low-resistance ball bearing inside vibrates and creates pressure in the airways. This vibration helps move stubborn mucus up and out of the lungs, making it easier to cough out and breathe more freely.
It's non-invasive, and doesn’t require medication — making it a parent-friendly option for supporting children post-respiratory infection or during mucus-heavy flare-ups. It’s easy to use — with parental assistance and supervision recommended, especially for younger children or first-time users.
Shop AirPhysio for Children at Aussie Pharma Direct.
Note: AirPhysio doesn’t “treat” or cure respiratory infections — it’s designed to support the body’s natural ability to clear mucus, helping to improve breathing comfort during the recovery process.
Optional extras to keep on hand:
While nothing replaces rest and fluids, a few tools can make home care easier and more comfortable:
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Thermometers – for tracking fevers with accuracy
- TouchBio 4in1 RSV, Covid, Flu A/B Combo Rapid Test Kit – a simple at-home test to check for RSV
- Soothing chest balms – formulated for children to help comfort and relax with gentle aromatic vapours (look for age-appropriate, natural options)
- Hand sanitisers – keeping hands clean is one of the simplest ways to stop viruses spreading. ViroCLEAR Hand Sanitiser is alcohol-free, TGA-listed, and gentle on little hands
- P2 face masks – if someone in the household is unwell or you're heading to a high-risk setting, AMD P2 Masks offer high-level respiratory protection for adults and older children
Conclusion: Know the cough, know what to do
Understanding what type of cough your child has, and how it lines up with conditions like RSV, croup, or bronchiolitis, can help you feel more in control of the situation.
Most of these illnesses are very common and can often be managed at home with rest, hydration, and a few helpful tools. But if something doesn’t feel right, trust your gut. Your instinct as a parent is one of your most valuable guides.
Staying informed, having the right products on hand, and knowing when to check in with your GP can help you move through cough season with more calm and confidence — even when things sound a little scary.
