They can also be described as unilateral or bilateral, as well as dry or moist/wet.īiphasic stridor suggests a subglottic or glottic anomaly Their presence usually indicates an airway disease, such as bronchiectasis. Coarse crackles are somewhat louder, lower in pitch, and last longer than fine crackles.The sounds from interstitial pulmonary fibrosis have been described as sounding like opening a Velcro fastener. Their presence usually indicates an interstitial process, such as pulmonary fibrosis or congestive heart failure. This sound can be simulated by rolling a strand of hair between one’s fingers near the ears, or by moistening one’s thumb and index finger and separating them near the ears. Fine crackles are soft, high-pitched, and very brief.They can also be characterized as to their timing: fine crackles are usually late-inspiratory, whereas coarse crackles are early inspiratory. Crackles are often described as fine, medium, and coarse.Crackles that do not clear after a cough may indicate pulmonary edema or fluid in the alveoli due to heart failure, pulmonary fibrosis, or acute respiratory distress syndrome.Ĭrackles that partially clear or change after coughing may indicate bronchiectasis.

Crackles are much more common during the inspiratory than the expiratory phase of breathing, but they may be heard during the expiratory phase.Ĭrackles are often associated with inflammation or infection of the small bronchi, bronchioles, and alveoli. Crackles are caused by the explosive opening of small airways.

Stridor lung sounds