Lung Sounds

Different sounds can be picked up through auscultation when air moves through the respiratory system. As a healthcare provider it is important to know the difference between each of the sounds so you can identify which actions (if any) need to be taken.

Rales/Crackles

A discontinuous bubbling/popping that may sound similar to velcro being pulled apart. Rales are heard on inhalation and can be further described as coarse, fine, moist, or dry.

Ronchi

A continuous, lower-pitched, coarse rattling sound that can be heard on both inspiration and expiration. Usually caused by blockage or secretions in the upper airway.

Stridor

A continuous, high pitched wheezing sound caused by disrupted airflow. Sometimes described as sounding “musical.” Mostly inspiratory but can ocassionally be heard on exhalation as well. Often caused by croup, infection, or a foreign object in the airway.

Wheezing

High pitched expiratory noise that can often be heard without a stethoscope. Caused by narrowed airways and associated with conditions such as asthma and COPD.