Stridor is an abnormal, high-pitched, musical breathing sound caused by a blockage in the throat or voice box (larynx). It is usually heard when taking in a breath.

See also: Wheezing

Breathing sounds - abnormal; Extrathoracic airway obstruction

Children are at higher risk of airway blockage because they have narrower airways than adults. In young children, stridor is a sign of airway blockage and must be treated right away to prevent total airway obstruction.

The airway can be blocked by an object, swelling of the tissues of the throat or upper airway, or spasm of the airway muscles or the vocal cords.

Common causes of stridor include:

• Abscess on the tonsils
• Airway injury
• Allergic reaction
• Croup
• Diagnostic tests such as bronchoscopy or laryngoscopy
• Epiglottitis, inflammation of the cartilage that covers the trachea (windpipe)
• Inhaling an object such as a peanut or marble (foreign body aspiration)
• Laryngitis
• Neck surgery
• Use of a breathing tube for a long time
• Secretions such as phlegm (sputum)
• Smoke inhalation or other inhalation injury
• Swelling of the neck or face
• Swollen tonsils or adenoids (such as with tonsillitis)
• Vocal cord cancer

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Stridor Treatment

Review Date: 04/26/2010
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)