- Inspiratory stridor : breathing sound when inhaling, typical for narrowing or obstruction of the upper airways ( larynx , trachea , main bronchi ). Example for causes: epiglottitis , croup , pseudocroup , thyroid enlargement ( goiter ), foreign body aspiration , benign or malignant tumors in the respiratory tract or on organs in the mediastinum , unilateral or bilateral vocal cord paralysis .
- Expiratory stridor : breathing sound when exhaling, typical of obstructive pulmonary diseases , such as B. Bronchial asthma
According to the localization of the narrowing, a distinction is made:
- Stridor nasalis : constriction in the nose ( nasus ), mostly as "sniffing"
- Stridor pharyngealis : Narrowing in the throat ( pharynx ), mostly as "snoring"
- Stridor laryngeal : constriction in the throat ( larynx ), mostly as a "whistling"
- Stridor trachealis : constriction in the windpipe ( trachea ), mostly as a "hum"