Croup is the most likely cause if your child suddenly develops a harsh, barky, seal-like cough along with a hoarse voice and noisy breathing, especially at night. But a regular cold, asthma, whooping cough, and a couple of rarer conditions can also cause a rough or noisy cough. This guide compares them side by side so you can spot the clues that set each one apart.

Croup (Laryngotracheobronchitis)

What it is: A viral infection that causes swelling in the upper airway, around the voice box and windpipe.

Why it happens: A common respiratory virus, often parainfluenza, inflames the lining of the airway and narrows the space air moves through.

Common symptoms: A sudden, loud, barky or seal-like cough, a hoarse voice or cry, and a harsh, crowing sound when breathing in (stridor). Symptoms often start or worsen at night and can ease somewhat with cool air or a steamy bathroom. A mild fever is common, and the cough sounds worse when the child is upset or crying.

Risk factors: Most common in children age 6 months to 3 years, and more frequent in fall and winter.

When to seek evaluation: Most croup can be managed at home, but stridor present even when the child is calm and resting is a reason to call the doctor that day.

Common Cold With a Cough (Viral Upper Respiratory Infection)

What it is: An ordinary viral infection of the nose and throat, one of the most frequent illnesses in young children.

Why it happens: Many common viruses spread easily among children, especially at daycare or school.

Common symptoms: A runny or stuffy nose, sneezing, a mild sore throat, and a cough that builds gradually over a day or two. It may sound wet or dry but lacks the barky quality of croup, and there is no stridor.

Risk factors: Time in group childcare settings and close contact with other sick children.

When to seek evaluation: Most colds resolve within one to two weeks. See a doctor if the cough lingers well past that, or if breathing looks labored.

Asthma or Reactive Airway Cough

What it is: Inflammation and narrowing of the small airways in the lungs, often triggered by a virus, allergens, exercise, or cold air.

Why it happens: The airways become sensitive and tighten in response to a trigger, making it harder to move air out of the lungs.

Common symptoms: A cough that is worse at night, with activity, or after a cold, sometimes with a whistling sound (wheeze) on breathing out. That is a key difference from croup, where the noisy sound happens on breathing in. Chest tightness and a history of eczema or allergies also point toward asthma.

Risk factors: A family history of asthma or allergies, or prior episodes of wheezing.

When to seek evaluation: A first episode of wheezing, or a cough that keeps recurring with colds or exercise, is worth discussing with a pediatrician.

Whooping Cough (Pertussis)

What it is: A bacterial infection of the airway that can cause severe, prolonged coughing fits.

Why it happens: The bacteria Bordetella pertussis irritates the airway lining, triggering intense bursts of coughing.

Common symptoms: It often starts like a mild cold, then progresses over a week or two into fits of rapid coughing, sometimes followed by a high pitched gasping "whoop" as the child breathes in. Vomiting after a coughing fit is common. Unlike croup, the whoop happens after a coughing spell, not at rest. Young infants may not whoop and can instead have pauses in breathing.

Risk factors: Incomplete vaccination, and infants too young to have finished the vaccine series.

When to seek evaluation: Any suspected whooping cough should be evaluated promptly, since it is contagious and treatable.

Foreign Body in the Airway

What it is: A piece of food or a small object that becomes lodged in the airway.

Why it happens: Toddlers explore with their mouths and can inhale small foods or toy parts while playing or eating.

Common symptoms: Sudden coughing, gagging, or choking in a child who was previously well, with no cold symptoms beforehand. There may be a one sided wheeze, and fever is usually absent early on.

Risk factors: Age 1 to 3 years, and small round foods such as grapes, nuts, or hot dogs, or small toy pieces.

When to seek evaluation: A witnessed or suspected choking episode with an ongoing cough or breathing trouble needs prompt evaluation, even if the child seems to recover.

Epiglottitis (Rare but Serious)

What it is: A rare, severe swelling of the flap of tissue that covers the windpipe, which can quickly block the airway.

Why it happens: A bacterial infection causes rapid swelling; it has become much rarer since routine Hib vaccination.

Common symptoms: A high fever, severe sore throat, drooling because swallowing is painful, a muffled voice, and a child who leans forward to breathe more easily. Unlike croup, a barky cough is often mild or absent, and the illness worsens quickly.

Risk factors: Being unvaccinated or under-vaccinated against Hib.

When to seek evaluation: This is a medical emergency; do not try to examine the throat at home, and seek immediate care.

How to Tell the Difference

Listen to the sound: A barky, seal-like cough with a harsh sound on breathing in points to croup. A whistle on breathing out points to asthma. A whoop that follows a coughing fit points to whooping cough.

Check the timing: Croup often appears suddenly at night in a child who seemed fine hours before. A cold builds gradually over a day or two. A foreign body causes an abrupt choking episode during play or a meal, with no illness beforehand.

Look at the other symptoms: Drooling, trouble swallowing, and leaning forward to breathe are not typical of croup and raise concern for epiglottitis. Vomiting right after a coughing spell fits whooping cough. A runny nose with a gradually worsening cough and no noisy breathing points to a simple cold.

Consider age and vaccine history: Croup is most common in toddlers and preschoolers. Whooping cough and epiglottitis are more likely, or more dangerous, in children who have not completed their vaccinations.

If you are unsure which pattern fits, the safest approach is to have your child seen. A pediatrician or urgent care visit can confirm croup with a simple exam and rule out the less common causes.

When to Seek Medical Care