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Croup is a viral infection that swells the airway around the voice box, so a young child gets a barking cough, a hoarse voice, and sometimes a noisy squeak when breathing in. Croup in toddlers is common, often worse at night, and usually mild. Stay calm, keep your child upright, and watch for trouble breathing.
What croup is, and who gets it
Croup is swelling of the voice box (larynx) and windpipe (trachea). In a small child that airway is narrow to begin with, so even a little swelling changes how breathing sounds and feels. An adult with the same virus would just have a sore throat and a hoarse voice.
The usual cause is a virus, most often a parainfluenza virus, although other cold viruses can do it too. Croup is most common in children between about 6 months and 3 years old, and the American Academy of Pediatrics notes that it can happen anywhere from 3 months to 5 years. It peaks in the fall and winter, but it can show up in any season. As children grow, their windpipe gets wider, which is why older kids tend to get a cold with a hoarse voice instead.
Because a virus causes it, croup spreads the way a cold does: through coughs, sneezes, shared cups, and unwashed hands. Antibiotics do not help, since they only work on bacteria.
What croup sounds like: the barking cough and stridor
Most children start with an ordinary cold. There is a runny nose, a mild cough, and maybe a low fever. After a day or two the cough changes. It turns harsh and barky, and many parents compare it to a seal. The voice gets hoarse, and the child may sound like they are talking through a rough pipe.
The sound that worries parents most is stridor. Stridor is a high, raspy or musical noise that you hear when your child breathes in. It is different from a wheeze, which is a whistle on the way out. A little stridor is common with mild croup, especially when a child is crying or running around. Stridor while your child is calm and resting is a bigger deal, and it is one of the main reasons to get medical help.
A barking cough at night is the classic first sign. Some children also have a spasmodic form of croup, which comes on suddenly in the middle of the night with no cold beforehand. Your child goes to bed fine and wakes up hoarse and gasping a few hours later. This version usually comes without a fever and can come back again. If it keeps recurring, mention it to your pediatrician.
Why croup is worse at night
Many parents notice that a child who seemed almost fine at dinner is coughing like a seal at 2 a.m. There are a few reasons, and doctors do not agree on exactly how much each one matters.
- Swelling can build up when a child lies flat for hours.
- Body rhythms shift overnight, and airway swelling and mucus tend to peak in the early morning hours.
- A child woken from sleep is scared. Crying makes the airway narrower and the cough worse, which feeds the cycle.
- Nights feel scarier for parents, so small changes in the sound seem bigger.
The second and third nights often feel a little better, and the days in between are usually calmer. It still helps to plan for the evenings. Keep your phone charged, know where your nearest emergency room is, and decide ahead of time who is on night duty.
How long croup lasts
Most cases of croup get better on their own. The worst of the barking cough usually lasts one to three nights, and the NHS says mild croup often improves within about 48 hours. The hoarse voice and a leftover cough can hang around for several days, often up to about a week, as the swelling goes down and the cold finishes. Your child may be tired and cranky during that time.
Call your pediatrician if your child is not getting better after a few days, if symptoms come back after seeming to improve, or if there is a new high fever. A new fever after a few days of improvement can mean a second infection.
Mild, moderate, or severe: how to size it up
Doctors group croup by how hard a child is working to breathe. You do not need to score your child, but knowing the groups helps you decide what to do next. Look at your child when they are calm, not mid-cry, because crying changes everything.
- Mild croup: a barking cough and a hoarse voice. There may be a little stridor when your child cries or is active, but none when resting. Your child is drinking, playing a little, and can be comforted. Home care is usually enough, but call the pediatrician's office the same day or at their next opening.
- Moderate croup: stridor even when your child is resting, faster breathing, and the skin between the ribs or at the base of the throat pulls in with each breath. Your child is more tired and less interested in drinking. This needs a medical visit soon, at an urgent care or an emergency room, because a doctor can give medicine that helps.
- Severe croup: loud stridor, clear struggling to breathe, deep pulling in of the chest or belly, very sleepy or limp, a gray or blue color, or too tired to cough. This is an emergency. Call 911.
Home care for croup, step by step
If the doctor or nurse line has said your child has mild croup, these steps help your child feel better and breathe easier.
- Stay calm and keep your voice soft. Children read your face. A panicked parent makes a crying child, and crying makes the airway narrower. Take a slow breath before you pick them up.
- Comfort first. Hold your child close, rock, sing, or read a quiet book. Skip anything that makes them cry, like forcing medicine or insisting they lie down.
- Keep them upright. Sit with your child on your lap, leaning against your chest. If they fall asleep, keep them propped up in your arms or sit beside them rather than laying them flat and leaving the room.
- Offer fluids. Small, frequent sips of water, breast milk, formula, or milk are best. A cold popsicle can be soothing for an older toddler. A child working hard to breathe may not want to drink, so watch for fewer wet diapers.
- Try cool air if it calms them. Some parents sit with their child near an open window, step outside for a few minutes in cool night air, or run a cool mist humidifier. The AAP points out that studies have not shown that steam or cool night air treats croup, so treat these as comfort measures, not treatment. The NHS advises against steamy rooms, and hot steam can scald, so skip the hot shower trick.
- Treat fever or discomfort if needed. See the next section for what is safe by age.
- Check on them often, including overnight. Look and listen to their breathing at regular intervals. Sleep in the same room if you can.
- Call for help if anything on the red flag list below appears. Do not wait for morning.
Fever reducers and cough medicine
Fever is common with viral croup, usually low but sometimes up to 104°F (40°C), according to the AAP. A fever reducer can help your child feel more comfortable, but it does not treat the croup itself. Use the age guidance below and ask your pediatrician for the right amount for your child's weight.
- Under 3 months: any fever of 100.4°F (38°C) or higher needs a call to your doctor right away. Do not give medicine first. Our guide to fever in babies explains why.
- 3 to 6 months: acetaminophen only, in the amount your doctor gives you.
- Older than 6 months: acetaminophen or ibuprofen, dosed by weight. Make sure your child is drinking, since ibuprofen is best given to a child who is taking fluids.
- Never give aspirin to a child.
Do not give over-the-counter cough or cold medicine to a toddler with croup. The AAP says cough syrups are not useful for croup and may do harm. The barking cough is how your child moves air past swollen tissue, and suppressing it does not fix the swelling. Honey is sometimes suggested for coughs, but it is never safe for babies under 12 months and it has not been shown to help croup, so ask your doctor before trying it.
What the doctor may do
Most children with croup never need more than home care. When treatment is needed, doctors rely on two main medicines, and neither is an antibiotic.
- A steroid. This reduces swelling in the airway. It is often given as a single dose of a steroid such as dexamethasone by mouth, with the amount based on your child's weight. It can also be inhaled or given by injection. The AAP says a few doses of steroids should do no harm and can ease symptoms and shorten time spent in the hospital.
- Nebulized epinephrine. For moderate or severe croup, an emergency team may give epinephrine (adrenaline) through a mask as a mist. It shrinks airway swelling quickly. Its effect wears off after a few hours, so children are watched for 3 to 4 hours afterward to make sure the symptoms don't return. Some children go home after that observation, and some stay in the hospital for more care.
The doctor will also listen to your child's chest, check oxygen levels if needed, and look at how hard your child is working to breathe. For spasmodic croup that keeps coming back, the doctor may look at allergy or reflux as a cause. You can read more about the medical side in the AAP's croup page on HealthyChildren.org.
Red flags: when to get emergency care
Most croup is mild. These signs mean your child needs to be seen right now. Call 911 or go to the nearest emergency room, even in the middle of the night. If your child is struggling to breathe, do not drive alone. Call for an ambulance or have someone else drive.
- Stridor while resting, or a whistling sound that gets louder with each breath.
- Skin pulling in between the ribs, under the ribs, or at the base of the throat with each breath (called retractions).
- Drooling, or trouble swallowing saliva. This can point to a different and more dangerous infection of the epiglottis.
- Blue, gray, or very pale lips, tongue, or face. On brown or Black skin, check the palms, the soles, and inside of the lips.
- Very sleepy, hard to wake, limp, or unusually quiet and still.
- Unable to speak, cry, or make sounds because of lack of breath.
- Very restless or frantic, and cannot be calmed.
- Breathing that is getting faster, harder, or more tiring, even after a few minutes of calm.
Children under 3 months with any croup-like symptoms should also be seen promptly, because their airways are even smaller and they can tire fast.
A realistic scenario
Picture a 2-year-old who has had a runny nose for two days. At 2 a.m. a harsh, seal-like bark comes from the bedroom. Dad finds his daughter sitting up, scared, and starting to cry. Each time she cries, the barking gets louder and there is a squeaky noise as she breathes in.
He doesn't lay her down. He sits on the floor with her against his chest, hums, and offers a few sips of water. Within ten minutes she's quieter. He listens while she rests: no squeak now, just a rough bark every few breaths. She is drinking, her lips are pink, and her ribs are not pulling in. He keeps her upright, watches her for another half hour, and calls the pediatrician's after-hours line, where the nurse agrees it sounds mild and tells him to bring her in the next morning. If the squeak had continued while she was calm, or if she had started drooling, he would have called 911 instead.
The order is what matters in this story: calm first, upright next, then look and listen to the breathing at rest. That pattern gives you the answer you need.
Croup vs RSV vs whooping cough
Several illnesses cause coughing in small children, and parents often wonder which one they are dealing with. Only a doctor can tell for sure, but the sounds are different.
- Croup: a barking, seal-like cough, a hoarse voice, and stridor when breathing in. It is an upper airway problem and is often worse at night. Our guide to a baby's first cold covers how these illnesses usually start.
- RSV: a runny nose and cough that moves down into the small airways. This can cause wheezing on the way out, fast breathing, and trouble feeding, and babies under 1 are most at risk. Our RSV season guide has more.
- Whooping cough (pertussis): long bouts of hard coughing, sometimes ending in a whoop as the child gasps in, and sometimes followed by vomiting. Young babies may not whoop at all and may pause their breathing instead. This is a bacterial infection that needs a doctor's care and is prevented by the DTaP vaccine series.
If you are not sure which one it is, let the breathing guide you. Any trouble breathing in a baby or toddler deserves a call to the doctor. You can also check our overview of common childhood illnesses for symptoms side by side.
Common mistakes parents make
- Laying a coughing child flat. Keep them upright and propped up while they are awake and until you are sure the breathing is easy.
- Letting panic show. Fear makes a child cry, and crying makes the stridor louder.
- Using hot steam. It has not been shown to work, and hot water and steam can burn a small child.
- Reaching for cough syrup. It does not treat croup, and it can cause harm in young children.
- Waiting out stridor at rest. If your child is calm and still makes a squeak with every breath, that deserves a medical visit today.
- Skipping the follow up. If the cough is no better after a few days or returns after a good stretch, call your pediatrician.
Myths vs. facts about croup
Myth: a steamy bathroom cures croup. Fact: the AAP says there are no studies proving that inhaling bathroom steam or cool night air helps, and the NHS advises against steam. Comfort and calm matter more.
Myth: croup needs antibiotics. Fact: croup is almost always caused by a virus, so antibiotics do not help. Steroids are the medicine that can.
Myth: a barking cough always means an emergency. Fact: the bark alone is not the warning sign. Trouble breathing is. Most children with croup are treated at home.
Myth: if the cough gets better in the morning, the illness is over. Fact: croup commonly eases during the day and flares again the next night. Keep watching for a couple of evenings.
How to lower the chance of croup
There is no vaccine for parainfluenza, the virus behind most croup, so you cannot prevent every case. Everyday habits help, because the same germs that cause colds cause croup.
- Wash hands often, especially before meals and after coming home from daycare or the store.
- Keep sick children home until the fever is gone and they feel well enough, and ask your pediatrician if you are unsure.
- Avoid sharing cups, spoons, and pacifiers during cold season.
- Keep up with vaccines. The yearly flu shot is recommended starting at 6 months, since flu can cause croup. The Hib vaccine protects against the bacteria behind epiglottitis, a dangerous cause of stridor that is now much less common. The DTaP vaccine protects against diphtheria, a rare cause of severe airway swelling, and against whooping cough.
- Avoid cigarette smoke around children. It irritates the airway and can make breathing problems worse.
When to call the pediatrician
Call the office the same day if your child has a barking cough and hoarse voice, even if they seem comfortable. The doctor can confirm croup, rule out other causes, and decide whether a steroid would help. Call again if your child is not drinking, has fewer wet diapers, has a fever that lasts more than a few days, or the symptoms return after improving. Our guide on when to call the pediatrician lists more warning signs, and the NHS page on croup has a plain summary of when to seek urgent help.
Trust your own sense too. You know how your child normally breathes and acts. If something looks wrong and you cannot say why, getting checked is always reasonable.
Frequently asked questions
What does croup sound like in toddlers?
Croup has a harsh, barking cough that many parents compare to a seal, along with a hoarse voice. Some children also make a high, raspy sound called stridor when they breathe in. A little stridor when crying is common. Stridor while resting, when your child is calm, is a reason to get medical help.
How long does croup last?
The worst barking cough usually lasts one to three nights. Mild croup often improves within about 48 hours, and a hoarse voice or leftover cough can last up to a week. If your child is not improving after a few days, or symptoms return, call your pediatrician.
Is it safe to treat croup at home?
Mild croup can usually be treated at home once a doctor or nurse line agrees. Keep your child calm and upright, offer fluids, use a fever reducer if needed for their age, and check on them through the night. Go to the emergency room if you see stridor at rest, pulling in between the ribs, drooling, blue or gray lips, or extreme sleepiness.
Does a steamy bathroom or cool night air help croup?
Studies have not proven that steam or cool night air treats croup. Some parents find that fresh air or a cool mist humidifier calms their child, which is fine as a comfort step. The NHS advises against steam, and hot steam can burn a small child. Calm and an upright position matter more.
What will the doctor do for croup?
Doctors often give a single dose of a steroid, such as dexamethasone, to reduce airway swelling. For moderate or severe croup, an emergency team may give nebulized epinephrine, then watch your child for 3 to 4 hours. Antibiotics do not help because croup is almost always caused by a virus.
Can I give my toddler cough medicine for croup?
No. Cough syrups do not help croup and can be harmful for young children. Use comfort measures and a fever reducer that is right for your child's age and weight. Ask your pediatrician before giving anything else, including honey, which is never safe for babies under 12 months.
