RSV or croup? A parent’s guide to symptoms, risks and when to seek care
October 3, 2025By: J. Michael Metts
Categories: Pediatrics Care
Overview: RSV or croup? Both respiratory infections can cause concerning coughs and restricted airways in young children. Learn the difference between these conditions so you can help your child get the care they need.
As a parent, hearing your child struggle to breathe or develop a sudden, harsh cough can be worrisome. During cold and flu season, two common respiratory illnesses, croup and respiratory syncytial virus (RSV), can cause these concerning symptoms. Understanding the differences between croup and RSV can help you respond quickly, confidently and calmly when your little one isn’t feeling well.
What is RSV?
Respiratory Syncytial Virus (RSV) causes swelling in the middle part of the lungs, called bronchiolitis. Most adults with RSV experience mild cold symptoms such as a runny nose, cough, sore throat and maybe a mild fever. But in young kids with smaller airways, the RSV can cause severe blockage and restrict their ability to breathe.
What does RSV sound like?
Young kids with RSV will often have a wet, persistent cough and make a wheezing or whistling sound when they exhale. If you notice any of these sounds in your child, it's time to see their pediatrician.
Who is most at risk for severe RSV?
Children under the age of 2, especially those younger than a year, are at the most risk for developing severe RSV symptoms. Babies who were born prematurely or have pre-existing health conditions are also at a higher risk.
When to see a doctor about RSV?
It’s time to seek medical assistance if your child is experiencing severe RSV symptoms such as:
- Difficulty breathing.
- Bluish or pale lips.
- High fever (over 100.4°F).
- Persistent or worsening wheezing.
- Extreme fatigue.
What is croup?
Croup is a respiratory infection, often caused by the parainfluenza virus. But unlike RSV which affects the middle part of the lungs, croup causes swelling in the upper airway. Once again, children with small airways are at the most risk for severe cases.
What does croup sound like?
Children with croup often experience a barky cough, which can worsen at night or when the child cries/is agitated. Children with severe croup cases can develop stridor. Stridor is a high-pitched or squeaky noise heard during inhalation.
When to see a doctor about croup?
You should see a doctor about croup if your child has stridor when calm, struggles to breathe, shows signs of dehydration, has a high fever or appears unusually tired or pale. If their lips or skin turns blue, or if symptoms worsen after a few days instead of improving, seek medical attention right away.
What can I do at home to help with croup?
If your child doesn’t have a severe case of croup, there are some simple ways to manage their symptoms at home:
- Keep them calm. Agitation or crying can worsen their symptoms.
- Make sure they are hydrated.
- Use humidifiers to add moisture to the air, which can soothe the inflamed and swollen tissues in a child’s upper airway. Make sure to change the water daily.
Seeking care for your child
Recognizing whether a child’s cough is barky like croup or wheezy like RSV can help parents respond appropriately, manage symptoms at home when safe and know when to seek medical attention. Early recognition can prevent complications and ensure children get the right treatment at the right time, whether it’s RSV or croup.
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