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Related to laryngeal stridor: congenital stridor




Stridor is a term used to describe noisy breathing in general, and to refer specifically to a high-pitched crowing sound associated with croup, respiratory infection, and airway obstruction.


Stridor occurs when erratic air currents attempt to force their way through breathing passages narrowed by:
Stridor can usually be heard from a distance but is sometimes audible only during deep breathing. Someone who has stridor may crow and wheeze when:
  • inhaling
  • exhaling
  • inhaling and exhaling
Most common in young children, whose naturally small airways are easily obstructed, stridor can be a symptom of a life-threatening respiratory emergency.

Causes and symptoms

During childhood, stridor is usually caused by infection of the cartilage flap (epiglottis) that covers the opening of the windpipe to prevent choking during swallowing. It can also be caused by a toy or other tiny object the child has tried to swallow.
Laryngomalacia is a common cause of a rapid, low-pitched form of stridor that may be heard when a baby inhales. This harmless condition does not require medical attention. It usually disappears by the time the child is 18 months old.
The most common causes of stridor in adults are:
  • abscess or swelling of the upper airway
  • paralysis or malfunction of the vocal cords
  • tumor.
Other common causes of stridor include:
  • enlargement of the thyroid gland (goiter)
  • swelling of the voice box (largyngeal edema)
  • narrowing of the windpipe (tracheal stenosis)
When stridor is caused by a condition that slowly narrows the airway, crowing and wheezing may not develop until the obstruction has become severe.


When stridor is present in a newborn, pediatricians and neonatologists look for evidence of:
  • heart defects inherent at birth (congenital)
  • neurological disorders
  • General toxicity.
If examinations do not reveal the reasons for the baby's noisy breathing, the air passages are assumed to be the cause of the problem.
Listening to an older child or adult breathe usually enables pediatricians, family physicians, and pulmonary specialists to estimate where an airway obstruction is located. The extent of the obstruction can be calculated by assessing the patient's:
  • complexion
  • chest movements
  • breathing rate
  • level of consciousness
X rays and direct examination of the voice box (larynx) and breathing passages indicate the exact location of the obstruction or inflammation. Flow-volume loops and pulse oximetry are diagnostic tools used to measure how much air flows through the breathing passages, and how much oxygen those passages contain.
Pulmonary function tests may also be performed.


The cause of this condition determines the way it is treated.
Life-threatening emergencies may require:
  • the insertion of a breathing tube through the mouth and nose (tracheal intubation)
  • the insertion of a breathing tube directly into the windpipe (tracheostomy)



Berkow, Robert, editor. The Merck Manual of Medical Information: Home Edition. Whitehouse Station, NJ: Merck & Co., Inc., 1997.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.


a shrill, harsh sound, especially the respiratory sound heard during inhalation with a laryngeal obstruction. adj., adj strid´ulous.
laryngeal stridor that due to laryngeal obstruction. A congenital form, marked by stridor and dyspnea, is due to an infolding of a congenitally flabby epiglottis and aryepiglottic folds during inspiration; it is usually outgrown by two years of age.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


A high-pitched, noisy respiration, like the blowing of the wind; a sign of respiratory obstruction, especially in the trachea or larynx.
[L. a harsh, creaking sound]
Farlex Partner Medical Dictionary © Farlex 2012


(strī′dər, -dôr′)
1. A harsh, shrill, grating, or creaking sound.
2. Medicine A harsh, high-pitched sound in inhalation or exhalation.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


ENT A harsh medium- to high-pitched crowing heard when breathing, especially on inspiration, due to an airway obstruction in the larynx or trachea; in children, stridor may occur in a background of congenital laryngeal stridor–laryngomalacia, which usually improves with age, or persists or recurs due to allergies, URIs, papillomas, foreign bodies, mediastinal masses, cysts of lung parenchyma
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


A high-pitched, noisy respiration, like the blowing of the wind; a sign of respiratory obstruction, especially in the trachea or larynx.
[L. a harsh, creaking sound]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


Noisy breathing caused by narrowing or partial obstruction of the LARYNX or TRACHEA.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005


A high-pitched, noisy respiration; sign of respiratory obstruction.
[L. a harsh, creaking sound]
Medical Dictionary for the Dental Professions © Farlex 2012
References in periodicals archive ?
The neurological examination and laboratory tests (hematology, biochemistry) were repeated and a consult of physical medicine and recovery was performed, strengthening the following diagnoses: sciatic popliteal nerve palsy, cerebral lacunarism, non-surgical right temporal meningioma, facial hemispasm, intermittent laryngeal stridor.
The patient is discharged with an improved mood, with possible walking, with an improvement regarding the laryngeal stridor, and with the recommendation to continue the psychiatric treatment and eventually to attend psychotherapy sessions, as far as it's possible, given the age and the educational level of the patient.
(7) In their article, entitled "Congenital laryngeal obstruction," they described a series of 18 patients with laryngomalacia, which they called congenital laryngeal stridor. In 1942, Jackson was the first to use the term laryngomalacia (from the Greek malakia: morbid softening of part of an organ); he defined it as a softness, flabbiness, or loss of consistency of laryngeal tissues.
A 20-year-old white man sought evaluation for a 7-month history of progressive shortness of breath and laryngeal stridor. Bronchoscopy revealed that a tracheal mass had occluded 90% of the tracheal lumen.
(1) Table Synonyms for hysterical stridor * Adult spasmodic croup Atypical asthma Benign vocal fold dysfunction Emotional laryngeal wheezing Emotional laryngospasm Episodic laryngeal dyskinesia Expiratory laryngeal stridor Factitious asthma Functional abduction paresis Functional inspiratory stridor Functional upper airway obstruction Functional vocal fold paralysis Laryngismus fugax Munchausen's strider Nonorganic upper airway obstruction Paradoxical vocal fold motion Pseudoasthma Psychogenic stridor Psychogenic upper airway obstruction Psychosomatic stridor Respiratory glottic spasm Transient laryngeal spasm * Based on information published by Snyder and Weiss.