Nasal flaring

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Nasal flaring is when the nostrils widen when you breathe. It is often a sign that you are having trouble breathing.

Alternative Names

Flaring of the alae nasi (nostrils); Nostrils - flaring


Nasal flaring is seen mostly in infants and younger children.

Any condition that causes difficulty breathing can cause nasal flaring. While many causes of nasal flaring are not serious, some can be life threatening.

In young infants, nasal flaring can be a very important symptom of respiratory distress.


Home Care

Seek immediate emergency help if you or your child has signs of a breathing difficulty.

When to Contact a Medical Professional

Call your health care provider if:

  • There is any persistent, unexplained nasal flaring, especially in a young child.
  • develops in the lips, nail beds, or skin. This is a sign that is severe. It may mean that an emergency condition is developing.
  • You think that your child is having trouble breathing.

What to Expect at Your Office Visit

The doctor or nurse will perform a physical exam and ask questions about the symptoms and medical history, such as:

  • When did the symptoms start?
  • Are they getting better or worse?
  • Is the breathing noisy, or are there wheezing sounds?
  • What other symptoms are there, such as sweating or feeling tired?
  • Do the muscles of the stomach, shoulders, or rib cage pull inward during breathing?

The doctor or nurse will listen carefully to the breath sounds. This is called auscultation.

Tests that may be done include:

Oxygen may be given if there is a breathing problem.


Wiebe RA, Scott SM. General approach to the pediatric patient. In: Marx J, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. St. Louis, MO: Mosby; 2011:chap. 164.

Version Info

  • Last reviewed on 5/14/2014
  • Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

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