Crackles: Sensitivity and Specificity

Introduction: Crackles are an adventitious sound heard when listening to lungs, which indicates fluid in the alveoli (e.g. from pneumonia, pulmonary edema). Note that many healthy individuals may have crackles at lung bases - in one study 34% of people age 65-79 had basilar crackles despite a normal echo and chest x-ray (Ann Fam Med. 2008 May-Jun;6(3):239-45 PMID: 18474887).