Croup - causes, symptoms and treatment

Baby coughing

Croup is very common in babies young children and, although it's usually easily treated at home, it can be frightening for parents to watch and pretty exhausting for you all to live through. The barking cough can sound really worrying – particularly if your child is also having breathing difficulties. Here's all you need to know about treating the symptoms and when to seek more help.

What is croup?

Croup is a very common respiratory infection that causes a harsh, barking cough, like a seal. It's usually caused by a virus that makes the bronchi (the airways to the lungs), trachea (windpipe) and larynx (voice box) swell up.

Croup mostly affects babies and toddlers of between six months and three years but children up to 15 can get it, too. It's more common in boys than it is in girls.

It's alarming to watch but, on the whole, croup sounds worse than it is. Literally, its bark is worse than its bite. Most cases last a few days – two weeks tops – and there should be no lasting damage.

Our son woke in the night with a horrible cough and was struggling to breathe. We took him to A&E. The doctor said he had croup. They gave him a steroid and sent us home. In the morning, he was okay and had just a normal-sounding cough.

Croup symptoms

The most obvious sign of croup is the distinctive cough. It sounds awful and is a noise certain to shred most parents' nerves but at least the bark-like sound will leave you in no doubt about what the problem is. Mumsnetters often say that, if your baby has croup, you’ll know about it. Most cases of croup occur during the autumn and winter and usually come on at night. You may well find you put a child with a bit of a rotten cold to bed and are woken in the early hours with full-on croup.

The cough sounds similar to a dog barking. The more upset the child becomes, the worse the barking becomes, and they can struggle to catch their breath.

Look out for the following symptoms:

  • Coughing (a dry, barking cough)
  • Fever
  • Runny nose
  • Sore throat
  • Hoarse voice
  • Stridor (a wheezing/rasping as the child inhales)

What does a croup cough sound like?

A croup cough is very distinctive and sounds somewhere between a seal noise and a dog barking. If you're unsure, have a look online where you'll find lots of recordings of croup coughs you can listen to so you can do a quick compare-and-contrast.

Baby coughing

Is croup contagious?

Yes. Croup spreads like the common cold so not only is it contagious, but you can get it more than once. It's most common in autumn and winter and if you're really unlucky you can even get it twice in one season. If your child has croup then you should keep her at home until she's better, not just to avoid passing it on but also because she'll probably be feeling pretty rotten and you're all likely to have had broken sleep as a result.

Can adults get croup?

It's very rare for anyone over the age of about six to get croup but it does sometimes happen, particularly in teens and young adults. As your airways grow and become stronger, it becomes less likely you'll pick up croup from any of the viruses that usually cause it. When it occurs in an adult it's called laryngitis, so if you’ve ever suffered from that you’ll have some idea of what your child is feeling.

What causes croup?

Croup is usually caused by viruses. Parainfluenza I is responsible for most cases (there are four strains of Parainfluenza and the other three are involved in a small percentage of cases). Other common causes of croup include:

  • Flu viruses
  • Measles (in children who haven’t been vaccinated against measles)
  • Common cold virus
  • Enteroviruses
  • Respiratory Syncytial Virus (RSV) which can cause severe breathing problems and, in babies, pneumonia.

Less common causes include:

  • Allergic reaction to pollen or dustmites
  • Acid leaking back out of the stomach and into the throat (reflux)
  • Epiglottitis – inflammation of the flap at the base of the tongue (epiglottis) that keeps food from going into the windpipe
  • Inhalation of chemicals
  • Inhalation of a small object, such as a pen cap or peanut.

Can croup be prevented?

While you can't actually prevent your child getting croup, anything you can do to avoid her picking up the viruses that cause it will help. So keep her out of contact with children you know are poorly. Also, some of the vaccines your child will be offered will protect her against some of the diseases that can cause croup, such as measles and flu, so keeping up to date with all of your child's vaccines will help.

Remember though, that croup is really common and most children make a full and swift recovery with no real drama, so it's not something to worry about too much. Just be aware of the symptoms so you can start treating them as soon as possible and know when to seek medical attention (see below).

How to treat croup

There is no need to be alarmed by croup but you should be proactive in treating it. If you think your child has anything more than just a mild case of croup, or you're at all worried, take her to your doctor. The NHS suggests you only need to visit a doctor or call 111 if you are concerned but most parents do just book a GP appointment to get it checked out. Often it's reassuring simply to have the problem diagnosed and check you're doing all the right things.

The way your child’s croup is treated will depend on the severity – another reason why a trip to the GP is often a good idea. In the vast majority of cases, treatment at home will be sufficient. As well as telling you about to treat croup at home, the doctor might prescribe a single dose of steroids to help reduce swelling in your child’s throat. This will make her more comfortable but be aware that side-effects can include:

  • Vomiting
  • Headaches
  • Upset stomach
  • Restlessness

In more severe cases, your GP might suggest a trip to hospital (see below).

Treating croup at home

Mild cases of croup are by far the most common and can usually be treated at home. Your GP will probably advise you give children’s paracetamol to ease the pain and reduce her temperature. Askm if you’re unsure about what other painkillers can be given to children and how regularly – and never give aspirin to a child under the age of 16. Also remember that, regardless of whether your child is old enough to have them, cough medicines and decongestants will have no effect on croup so don't bother with them.

Along with giving your child any medicines advised or prescribed, there are plenty of things you can do to ease her pain and comfort her while she recovers. Here are a few things you can do to help:

  • Sit her upright on your lap or on your shoulder to help her breathing as this position keeps her airways more open.
  • Give her plenty of fluids to drink, as this will soothe her sore throat and help prevent dehydration. Young babies can have extra breastmilk or formula and water. Children who are weaned can be given fruit juice and soup, too, which will give them a bit of extra energy as well as soothing a sore throat


  • Never underestimate the power of a good cuddle. Children, understandably, can find croup really upsetting but crying will actually make her symptoms worse so anything you can do to keep her calm and comfortable will help.
  • Stay close. You might find you want to make up a bed (or a heap of cushions on the floor) in your child's room while the cough is really bad. If she gets distressed you'll be on hand quickly, and you may find you sleep better yourself for not trying to strain one ear all night listening out for her if you don't have a baby monitor.

Can you treat croup with steam or cold air?

Some Mumsnetters say that moist or cold air can help to reduce swelling in the airways. Many parents recommend taking your child into a steamy bathroom, where you run a hot bath or leave the shower on, and letting her breathe the steamy air. Alternatively, others have found wrapping her up warm and taking her outside for a breath of cool air helps.

While these might be worth a go, there's no hard evidence to indicate that the steam/cold air techniques work and even their advocates acknowledge that they won’t cure croup and are simply quick fixes to ease coughing and breathing difficulties. The NHS actually advocates against it, but many doctors will still tell you that anecdotally it helps. If you do use the steam inhalation method, make sure you don't allow your child anywhere near the hot water source as she can easily scald herself.

Croup: when to worry

Occasionally croup can become severe and cause complications such as pneumonia or pulmonary oedema. Because the barking cough of croup can sound really bad, even with a mild case it can be hard to know when to stay calm and when to call 999. Here's a checklist to help you decide.

It's a good idea to see your GP or call 111 for advice if:

  • You're at all worried
  • You feel the croup is getting worse
  • Your baby is very young (below a year)
  • Your child has any other medical conditions that might make things worse

Even if your child has been diagnosed with a mild case of croup, you should monitor her symptoms to see how she responds to treatment. If you think she’s getting worse rather than better, return to the doctor immediately and see if they think she might be suffering from a severe case of croup that requires hospital treatment.

You should call 999 or take your child to A&E if your child has croup and also:

  • Is struggling to breathe
  • Has a blue tinge to the lips or face
  • Has a drawn-in neck or ribcage
  • Seems to be sucking in her tummy as she breathes
  • Is quiet or unusually lethargic
  • You just feel 'something isn't right'. Parental intuition is often spot on and medical staff would always rather send home a child who turns out to be fine than see them seriously ill

How are severe cases of croup treated?

If your child goes to hospital, either on your GP's advice or because you have taken her there or called an ambulance, the doctors’ priority will be to stabilise her breathing. If she’s distressed, then she might be given an oxygen mask. Otherwise, she will probably be given adrenaline through a nebuliser (this turns medication into a fine mist which your baby can breathe in). This treatment usually has an immediate effect and get her breathing steadily within 30 minutes.

We called an ambulance for my son when he was unable to breathe with croup. Don't be afraid to go to A&E or call an ambulance if your child is having difficulty breathing.

In very rare cases, intubation might be needed. This is when a tube is inserted into the windpipe, via the mouth or a nostril, to help the child breathe. Distressing as this might be, it will at least be done under general anaesthetic, so the child will be unconscious during the procedure and unaware of what’s going on.

This might all sound a bit terrifying, but remember only around 1-5% of children with croup end up in hospital and the vast majority of children make a full recovery quickly. Mumsnet Talk is an excellent place for discussing your worries or experiences with other parents who’ve been there – and it's open 24/7.

How long does croup last?

In most cases the worst is over in a day or two, but symptoms can last up to a week, and even up to a fortnight sometimes if your child has trouble shaking it off.