Symptoms of Stridor

Stridor is the medical term for noisy breathing that is heard when turbulent airflow passes through a narrowed segment of the upper airway. Stridor is heard during inspiration (breathing in or inhaling), or is heard during both inspiration and expiration (taking a breathing out or exhaling). Stridor is often described as a high pitched musical sound. People with stridor often have shortness or breath (dyspnoea) as well. Stridor is sometimes mistaken for wheeze or stertor, which are also sounds from the respiratory tract. Subglottic stenosis, vocal fold paralysis, laryngeal infections and tumours in the throat are some of the many conditions associated with this.

Wheeze is a musical sound that may be low or high pitched, and is produced by reduced airflow in the lower respiratory tract. Wheeze is usually heard during expiration. Asthma and emphysema are associated with wheeze.

Stertor is alow pitched sound that is caused by vibration of tissue in the throatowing to obstruction of the airway above the vocal folds. Stertor is described as low in pitch and not musical. It is heard during inspiration. Simple snoring, upper airways resistance syndrome, obstructive sleep apnoea and adenotonsillar enlargement are all associated with stertor.

How do we evaluate stridor?

People with stridor are initially evaluated by taking a thorough medical history and by performing an examination of the upper airway, including endoscopy. There are two types of endoscopy: standard endoscopy of the throat (laryngoscopy),and tracheoscopy. Both procedures involve the passage of an endoscope (a slim tube with a camera on the end) through the noseusing local anaesthetic to examine the airway. A tracheoscopy involves passing the endoscope between the vocal folds into the trachea (windpipe) to examine the lower part of the airway. Both are performed in the office. Additional investigations such as CT scanning, and/or examination under anaesthesia may be required to confirm the diagnosis.