Crackles heard in the lungs of a person with pneumonia using a
stethoscope. |Problems listening to this file? See media help.|
Crackles, crepitations, or rales (i// RAHLS or // RALS) are the
clicking, rattling, or crackling noises that may be made by one
or both lungs of a human with a respiratory disease during
inhalation. They are often heard only with a stethoscope ("on
auscultation"). Bilateral crackles refers to the presence of
crackles in both lungs. Basal or basilar crackles (not to be
confused with the basilar artery of the brain) are crackles
apparently originating in or near the base of the lung. Bibasal
or bibasilar crackles refer to crackles at the bases of both the
left and right lungs. Bilateral basal crackles also refers to
the presence of basal crackles in both lungs. Crackles are
caused by the "popping open" of small airways and alveoli
collapsed by fluid, exudate, or lack of aeration during
expiration. The word "rales" derives from the French word râle
meaning "rattle". Crackles can be heard