Stridor is a high-pitched, wheezing sound caused by disrupted airflow. Stridor may also be called musical breathing or extrathoracic airway obstruction.

Airflow is usually disrupted by a blockage in the larynx (voice box) or trachea (windpipe). Stridor affects children more often than adults.

Types of stridor

There are three types of stridor. Each type can give your doctor a clue about what is causing it.

Inspiratory stridor

In this type, you can only hear the abnormal sound when you breathe in. This indicates an issue with the tissue above the vocal cords.

Expiratory stridor

People with this type of stridor only experience abnormal sounds when they breathe out. Blockage in the windpipe causes this type.

Biphasic stridor

This type causes the abnormal sound when a person breathes in and out. When the cartilage near the vocal cords narrows, it causes these sounds.