That sudden, harsh “barking” cough at 2 a.m. can make any parent sit bolt upright. Add a hoarse voice, noisy breathing, and a child who looks unsettled, and croup quickly feels bigger than it is. The reassuring part? Most episodes of croup improve well with the right support.
What usually helps is simple but specific: know what croup typically looks like, calm the breathing, keep fluids going, and recognise the signs that need a doctor quickly.
What croup is (acute viral laryngotracheitis)
Croup is an infection that inflames the upper airway, mainly the larynx (voice box) and the upper trachea (windpipe). You may hear the medical name acute viral laryngotracheitis.
Children’s airways are naturally narrow. So when croup causes swelling, even a small change can make breathing sound loud and feel effortful.
Where the swelling happens: the subglottic area
In classic croup, swelling is often worst just below the vocal cords, called the subglottic region. In babies and toddlers, this area is tight to begin with. A few millimetres of swelling can reduce airflow a lot, hence the drama in the sound, even when the illness is still mild overall.
Why the cough becomes “barky” and breathing can whistle in
When air squeezes through a narrowed upper airway:
- the cough turns “seal-like” or barking
- the voice becomes hoarse (the vocal cords are irritated)
- a high-pitched sound may appear when breathing in: stridor (different from wheeze, which is usually on breathing out)
Typical timeline: why nights feel worse
Many children with croup start with a simple cold: runny nose, congestion, maybe mild fever. Then the barky cough and stridor peak at night, often in the first 1–2 nights.
Common pattern:
- looks better in the morning and afternoon
- worsens after bedtime
- clear improvement often appears within ~48 hours
- symptoms usually settle in 3–7 days, though a cough or hoarseness can linger
Why the night flare? Lying down, fatigue, and dry indoor air can make swelling feel more obvious. Also, distress fuels distress: crying increases airflow turbulence, and stridor sounds louder.
Is croup contagious? (Yes, like a common cold)
Yes. Croup is usually caused by common respiratory viruses and spreads through droplets (coughing/sneezing) and contaminated hands and surfaces. In Indian households with close contact, siblings sharing rooms, grandparents helping, more than one family member may catch the virus, though adults usually get only a sore throat or cold.
Who gets croup most often
Croup is most common between 6 months and 3 years, often around 1–2 years. Toddlers are more affected because their airway diameter is smaller, so swelling causes proportionately more narrowing.
Infants: why doctors may be more cautious
Very young babies can struggle sooner because:
- their airway is tiny
- feeding can drop quickly if breathing is hard
- they rely heavily on nasal breathing (a blocked nose adds to the load)
If a small infant has stridor, breathing difficulty, or poor feeding, prompt medical assessment is sensible.
Children who may need earlier evaluation
Some children need a lower threshold for review:
- prematurity history
- prior airway or lung problems
- episodes that seem unusually severe or recurrent
What causes croup (and what can worsen it)
Most croup is viral.
Common viruses:
- parainfluenza virus (frequent)
- RSV, influenza A/B, adenovirus, rhinovirus, enterovirus
- SARS-CoV-2 can also present with croup in some children
Even when a virus is the trigger, irritants can worsen coughing and swelling:
- cigarette smoke (including second-hand and third-hand exposure)
- vaping aerosols
- strong room fresheners, sprays, incense smoke in a closed room
- very dry air or overheating the bedroom
Recurrent episodes: possible contributors
If your child gets croup repeatedly, clinicians may consider ongoing irritation such as GERD (reflux) or atopy (allergic tendency). This is not about hunting for one perfect explanation, it’s about reducing repeated throat inflammation over time.
What croup sounds like: stridor vs wheeze
Parents often ask, “Is that from the chest?”
- Stridor: high-pitched sound mainly on breathing in → upper airway narrowing, typical of croup.
- Wheeze: whistling mainly on breathing out → lower airway narrowing (asthma/bronchiolitis).
If wheeze dominates, or both wheeze and stridor are present, clinicians may look beyond straightforward croup.
Symptoms of croup: mild, moderate, severe
Classic croup symptoms:
- barking cough
- hoarse voice
- stridor (especially on inspiration)
Often there are cold symptoms first and sometimes fever.
A practical way to judge severity: observe when calm
- Mild: barky cough, stridor only when crying/active, comfortable at rest.
- Moderate: stridor at rest, visible effort to breathe.
- Severe: stridor at rest plus very hard breathing, poor air movement, or exhaustion.
Signs of increased work of breathing
Look for:
- retractions (skin pulling in between ribs, above collarbones, or at the base of the neck)
- fast breathing
- nasal flaring
- difficulty speaking/crying normally because breathing is hard
Fever: what matters more than the number
Fever may be mild or absent in viral croup. Breathing effort, alertness, and drinking matter more than the exact temperature reading.
Hydration: the under-noticed issue
When breathing is hard, drinking becomes tiring.
Watch for:
- shorter feeds, frequent pauses
- fewer wet nappies/diapers
- dry mouth, reduced tears
When to seek urgent or emergency care
Trust what you see, not only what you hear.
Emergency red flags (seek immediate help)
- stridor at rest that is persistent or worsening
- marked retractions or very fast breathing
- blue/grey lips or face
- pauses in breathing
- your child appears to struggle for each breath
Behaviour changes that can signal fatigue
Get urgent help if your child is:
- extremely agitated and cannot be soothed
- unusually sleepy, less responsive, or exhausted
A very quiet child with severe croup can be a sign of tiredness, not comfort.
Feeding and hydration concerns
Seek urgent assessment if your child:
- cannot drink or breastfeed
- vomits repeatedly
- has a very dry mouth
- has far fewer wet nappies/diapers than usual
Warning signs for serious look-alikes (do not wait)
These are not typical of simple viral croup:
- drooling
- difficulty swallowing
- muffled “hot potato” voice
- sudden onset with high fever and significant throat pain
- sudden symptoms after choking (possible foreign body)
How croup is diagnosed (and when tests help)
Doctors usually diagnose croup clinically, based on age, recent cold, barking cough, stridor, breathing effort, and hydration.
- Pulse oximetry may be used to check oxygen saturation, especially in moderate-to-severe cases.
- Blood tests are usually not useful.
- Neck X-ray (sometimes showing the “steeple sign”) is not routine, it may be used when symptoms are atypical or severe.
Recurrent episodes, poor response, or illness outside the usual age range may lead to further evaluation.
How clinicians grade severity: the Westley score
Some clinicians use the Westley croup score to standardise assessment and response to treatment. It considers:
- stridor
- chest wall retractions
- air entry
- cyanosis
- level of consciousness
Scores support decisions on observation and medication, but clinical judgement still leads.
Conditions that can look like croup
Not every noisy breath is croup.
Doctors also consider:
- epiglottitis (rare but emergency): high fever, drooling, severe sore throat, difficulty swallowing, rapid worsening
- bacterial tracheitis: higher fever, sicker appearance, poor response to usual croup treatment
- foreign body aspiration: sudden onset during eating/play
- bronchiolitis/asthma: wheeze and chest signs
- anaphylaxis/angioedema or deep neck infections: swelling, drooling, muffled voice, neck pain/stiffness
Medical treatment for croup
Corticosteroids (dexamethasone): mainstay
For most children with croup, a single dose of dexamethasone is the standard first-line treatment. A commonly used dose is 0.6 mg/kg, usually by mouth (or injection if needed).
Parents often notice easier breathing within a few hours, and the next night is usually better.
In some settings, nebulised budesonide may be used as an alternative steroid option.
Nebulised epinephrine: for moderate-to-severe cases
For croup with stridor at rest and significant distress, clinicians may give nebulised epinephrine. It can work fast, but the effect may wear off after about 2–4 hours, so observation (often at least 2 hours) is needed to watch for rebound symptoms.
Supportive care in hospital
- oxygen if saturation is low
- monitoring
- a calm environment (distress worsens upper-airway narrowing)
What usually does not help
- antibiotics (unless a bacterial infection is suspected)
- humidified mist as a “replacement” for steroids/epinephrine
Home care for mild croup (safe, practical steps)
If your child is comfortable at rest and stridor is only when upset, home support is often enough.
1) Calm first: break the distress–breathing loop
Hold your child upright or semi-upright. Keep the room quiet. Speak softly. Small steps, big impact.
2) Fluids: little and often
Prioritise hydration over appetite. Offer frequent small sips (or more frequent breastfeeds/formula feeds). Track wet nappies.
3) Clear a blocked nose
Saline drops/spray and gentle suction before feeds and sleep can help, especially in infants.
4) Fever and pain relief
Paracetamol (acetaminophen) or ibuprofen can be used with correct weight-based dosing. Avoid aspirin. Avoid OTC cough/cold combinations in young children unless a clinician specifically advises.
5) Air: keep it safe
If your home air is very dry, a clean humidifier may improve comfort.
Avoid hot steam close to your child (burn risk). Some families find cool night air briefly soothing, if you try it, keep your child warm and supervised.
Things to avoid at home
- smoking in the home or balcony near the child
- vaping aerosols
- strong sprays/room fresheners/incense in closed rooms
- overheated bedrooms
- menthol/camphor rubs in small children as a “treatment” for breathing noise
A simple night plan
Ask yourself:
- When my child is calm, is there stridor at rest?
- Are retractions increasing?
- Is my child too tired to drink?
If yes to any, or if you feel uneasy about breathing effort, seek urgent care rather than waiting for morning.
Different patterns: viral croup, spasmodic croup, recurrent episodes
- Typical viral croup follows a cold, peaks at night, improves over a few days.
- Spasmodic croup can start suddenly at night and improve by morning, it may recur for 1–2 nights. Airway sensitivity, dry air, irritants, or allergy tendency may contribute.
If episodes are frequent, unusually severe, prolonged, or outside the usual age range, discuss with your paediatrician.
Complications and prognosis
Most children recover well from croup, often with clear improvement within 48 hours.
Possible complications:
- dehydration (common and easy to miss)
- worsening respiratory distress as fatigue builds
- less commonly, pneumonia or bacterial tracheitis (think higher fever, toxic appearance, poor response)
Hospitalisation is more likely with persistent stridor at rest, repeated need for nebulised epinephrine, low oxygen saturation, significant fatigue, or inability to maintain hydration.
Prevention: reducing spread and throat irritation
- handwashing with soap and water for 20 seconds
- cough/sneeze into tissue or elbow
- clean high-touch surfaces (toys, handles) and ventilate rooms
- keep a child home with fever and significant respiratory symptoms, return when fever-free for 24 hours without fever reducers and overall improving
- avoid smoke exposure and strong indoor irritants
- vaccines matter: influenza vaccine reduces flu-related croup-like illness, Hib vaccine helps prevent severe upper-airway infections that can mimic croup
Key takeaways
- Croup is an upper-airway infection causing barking cough, hoarseness, and sometimes stridor, often worse at night.
- The first 1–2 nights can look dramatic, many children improve within about 48 hours, with symptoms lasting roughly 3–7 days.
- Home care for mild croup focuses on calming, upright positioning, small frequent fluids, and clearing nasal congestion.
- Seek urgent care for stridor at rest, increasing work of breathing (retractions, nasal flaring, very fast breathing), blue/grey colour, dehydration, or unusual drowsiness/exhaustion.
- Clinicians commonly treat croup with dexamethasone, nebulised epinephrine is used for more severe symptoms with observation.
If you want extra support, your paediatrician and local emergency services can assess breathing quickly. You can also download the Heloa app for personalised tips and free child health questionnaires.
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