What is Croup?

What is Croup?

Croup is caused by inflammation that partially obstructs the upper airway. It is a common respiratory condition in most children that presents with a barking cough and noisy breathing.

Croup most frequently develops in children aged six months to five years old, with peak time being around two years old. Croup is more likely to appear in the fall and winter seasons.

A croup cough can sound like a barking seal. It is also accompanied by a hoarse voice and noisy breathing due to the narrowing of the airway. This narrowing can be dangerous for children and often requires urgent evaluation by medical providers.

Types of Croup


There are two common types of croup:

  • Viral croup. Viral croup, or laryngotracheobronchitis, is caused by a viral infection that leads to swelling of the larynx (voice box) and subglottis (upper windpipe). This is the most common type of croup.
  • Spasmodic croup. Spasmodic croup occurs in the absence of a viral infection and is believed to be caused by inflammation from an allergy or reflux from a child’s stomach.

Signs & Symptoms of Croup


Viral croup occurs in the setting of an upper respiratory infection, so typically, there will be signs of a cold before the onset of croup symptoms. Symptoms of croup generally last three to five days and can worsen at night.

Typical symptoms of croup include:

  • Loud, barky cough
  • Hoarseness of the voice
  • Loss of voice
  • Stridor, a high-pitched breathing noise that comes from the throat area
  • Labored breathing

Seek immediate medical attention if your child develops severe symptoms such as stridor or has trouble breathing.

Is croup contagious?

Most of the time, croup occurs in the setting of a virus. The virus that causes croup can be contagious and is spread through coughing, sneezing, or exposure to other respiratory excretions. However, just because the virus may be spread to others from someone with croup does not mean they will develop croup.

What Causes Croup?


Viruses cause most cases of croup, but it can also be caused by inflammation due to other things, such as allergies or reflux from the stomach.

Viruses that can cause croup to include respiratory viruses:

  • Parainfluenza virus
  • Influenza virus
  • Enterovirus
  • Rhinovirus
  • Adenovirus
  • Respiratory syncytial virus (RSV)
  • SARS-CoV-2 (COVID-19)

Risk Factors

Risk Factors

The primary risk factor for croup is age, as young children’s airways are smaller and more vulnerable to swelling during infections. A child is most susceptible to croup from six months to five years of age during the winter season. Other predisposing factors include patients with narrow or malacic (floppy) airways due to underlying medical conditions.



Any young child can come down with croup, but there are certain precautions one can take to either prevent croup or reduce the likelihood of developing the condition. Preventive methods that could help avoid croup include:

  • Keeping your child away from a sick individual
  • Hand washing
  • Sneezing or coughing in the elbow vs. the hand
  • Keeping up-to-date on your child’s vaccinations to prevent more serious infections
Get Care

Trust NewYork-Presbyterian for Croup Care

Having a child with croup can be unpleasant and exhausting for caregivers. The caring pediatric staff at NewYork-Presbyterian can reassure parents and offer treatment options for mild croup symptoms and solutions for more serious cases.

Have questions about your child’s symptoms? Reach out to NewYork-Presbyterian for a consultation or appointment with one of our pediatric experts.