Croup in Children at Night: Recognise It, Help Immediately, Know When to Call 999

It's 3 am. Your child wakes up with a cough that sounds like a barking seal. There's a harsh, rasping noise on every breath in, a hoarse voice, and visible effort with each breath. You don't know what this is — and you don't know whether you need to leave for A&E right now.

This is croup. And the most important thing first: most episodes are mild and resolve on their own. But you do need to know the warning signs that signal a genuine emergency. You'll find them just below.

What Is Croup — and Why Does It Always Happen at Night?

Croup is a viral inflammation of the lining of the larynx (voice box), below the vocal cords. As the lining swells, the airway narrows — that's what causes the barking cough, the hoarseness, and the rasping sound on breathing in (stridor). According to the BVKJ (German Association of Paediatrics), croup mainly affects children aged between 3 months and 5 years, whose airways are still narrow.

Episodes almost always come on in the evening or at night. During the day, children are typically symptom-free. The trigger is usually a common viral respiratory infection — most often parainfluenza viruses, less commonly RSV, rhinoviruses, or other cold viruses. Croup is more common in autumn and winter than in spring or summer.

An important distinction: "croup" in historical medical texts sometimes referred to diphtheria (true croup). What parents face today is viral croup — a different, generally milder condition. Vaccination has made diphtheria very rare. The inflammation here sits below the vocal cords, not at the epiglottis.

Which Warning Signs Mean: Call 999 Right Now?

Croup can range from mild to severe. The following are signs that your child needs emergency medical care immediately — regardless of how the episode started:

Most croup episodes do not show these signs. But knowing them means you can act without hesitation if they appear.

What Should You Do Right Away — The First Minutes After Your Child Wakes?

When your child wakes with a barking cough, two things matter most: your calm and cool air. Anxiety is contagious — crying and distress make breathing harder by tightening the muscles around an already narrowed airway.

Step by step:

1. Stay calm. Speak in a steady, reassuring voice. Pick your child up or sit them upright.
2. Cool air. Open a window or take your child outside into the cool night air — even in winter. Breathing cool air is the best-supported first-aid measure for croup.
3. Keep them upright. Don't lay your child flat. Sitting or being held upright makes breathing easier.
4. Small sips of cool fluid. Water or diluted juice — nothing hot.
5. Steroid suppository, if prescribed. If your GP has given you a corticosteroid suppository for emergencies, use it now. Corticosteroids reduce the swelling reliably and are safe in acute croup.

When Should You Contact a GP or NHS 111 — Even Without an Emergency?

After a first episode of croup, your child should always be seen by a GP — even if the episode was mild and settled on its own. Your GP can confirm the diagnosis, rule out other causes, and prescribe a corticosteroid suppository to keep at home for future episodes.

During the night or out of hours: Call NHS 111. They can assess severity over the phone and advise on whether a trip to A&E is needed.

Contact your GP soon (same day or next available appointment) if:

• The episode has resolved but your child is unusually sleepy or refusing fluids afterwards
• You are not sure whether this was croup or something else
• Your child has a fever that lasts more than 2–3 days
• The barking cough continues during the day (unusual for croup — other causes need ruling out)

What If the Barking Cough Happens During the Day?

Croup typically strikes at night; daytime episodes are unusual. A barking cough with stridor during the day should always be assessed by a GP or at A&E — other causes such as an inhaled foreign body or bacterial epiglottitis need to be excluded.

How Is Croup Different From Whooping Cough and Other Respiratory Conditions?

Not every barking cough is croup. A quick guide:

Feature	Croup	Whooping cough (pertussis)	Epiglottitis
Cough	Barking, seal-like	Rapid bursts, gagging, whooping on breath in	Little or none
Voice	Hoarse	Normal or hoarse	Muffled, "hot potato"
Fever	Mild to low-grade	Initially cold-like	Usually higher
Onset	Sudden, at night	Gradual over weeks	Rapid, within hours
Swallowing	Normal	Normal	Painful; drooling
What to do	First episode: GP / NHS 111; 999 if severe	Always see GP to confirm diagnosis	Call 999 immediately

How to Track the Episode for Your GP

Having these details ready means faster and better help:

• When did the cough start — what time, how suddenly?
• How long did the episode last?
• What did it sound like — barking, rasping, stridor on breathing in or out?
• What helped — cool air, sitting upright, how quickly?
• Fever — how high, since when?
• Preceding illness — had your child had a cold or runny nose in the days before?
• First episode or recurrence?

Frequently Asked Questions About Croup

Is croup contagious?

The underlying cold virus is contagious — but not every child who catches it develops croup. Whether it happens depends on the individual shape of a child's airways and their sensitivity to the virus. Croup itself is not a separately contagious condition; it is the body's response to the viral infection.

How long does a croup episode last?

Most episodes ease significantly within a few minutes once the child is calm and breathing cool air. According to IQWiG (Gesundheitsinformation.de), most children have only mild symptoms that resolve on their own within two days. Episodes often recur over several nights — children are typically fine during the day.

Can I give my child the corticosteroid suppository at home?

Only if your GP has prescribed one and explained how to use it. Corticosteroids are safe and effective in acute croup — but the correct dose must be agreed with your GP. Without a prescription: call NHS 111 or go to A&E.

Why does the NHS say not to use steam?

The NHS is explicit on this: do not use a steamy bathroom. There is no good evidence that steam helps with croup, and hot steam carries a risk of scalding a distressed, wriggling child. Cool air is safer and better supported.

What age can children get croup?

Croup mainly affects children aged 3 months to 5 years, when the airways are still narrow. As children grow, episodes become less frequent and milder. Older children and adults can still get croup, but it is usually very mild. Children under 3 months with any breathing difficulty should be assessed urgently — contact your GP or NHS 111, and call 999 if your baby seems very unwell.

Does croup only happen in autumn and winter?

No, but it is more common in the colder months. A summer episode is unusual enough that it is worth checking in with your GP, as other causes may need ruling out.

Can croup come back?

Yes. Some children have one episode and never again; others have several episodes each winter. As the airways grow, episodes become rarer and milder. If your child has recurrent croup, talk to your GP about keeping a corticosteroid suppository at home for acute episodes.

Summary: What to Do With Croup at Night

Situation	What to do
Severe retractions, blue/grey lips, drooling, unable to swallow	Call 999 / go to A&E
Stridor at rest, no improvement after cool air for a few minutes	Call 999 / go to A&E
First episode, even if mild and resolved	Call NHS 111 or see your GP next day
Episode easing, child calming, stridor improving with cool air	Observe, keep upright, cool air
Barking cough during the day, or fever lasting several days	GP appointment soon