The main breathing abnormalities are:
 Crackles
 Wheezes
 Pleural Rub
Crackles:
Crackles (rales) are caused by excessive fluid in the airways. It is caused by either an
exudate or a transduate. Exduate is due to lung infection e.g pneumonia while
transduate such as congestive heart failure.[1] A crackle occurs when a small airways
pop’s open during inspiration after collapsing due to fluid or lack of aeration during
expiration. [2] Crackles are much more common in inspiratory than in expiratory.
Crackles are high-pitched and discontinuous. They sound like hair being rubbed
together. [3] There are three different types; fine, medium and coarse.
 Fine are typically late inspiratory and coarse are usually early inspiratory
 Fine crackles are high pitched, very brief and soft. It sounds like rolling a
strand of hair between two fingers. Fine crackles could suggest an interstitial
process; e.g pulmonary fibrosis, congestive heart failure.
 Coarse crackles are louder, more low pitched and longer lasting. They sound
like the separation of Velcro. Coarse crackles could suggest an airway disease,
chronic bronchitis. [4]
Wheezes:
Wheezes are an expiratory sound caused by forced airflow through collapsed airways.
Due to the collapsed or abnormally narrow airway, the velocity of air in the lungs is
elevated. [1] Wheezes are continuous high pitched hissing sounds. They are heard
more frequently on expiration than on inspiration. If they are monophonic it us due to
an obstruction in one airway only but if they are polyphonic than the cause is a more
general obstruction of airways. [5] Where the wheeze occurs in the respiratory cycle
depends on the obstructions location, [6] if wheezing occurs in the expiratory phase of
respiration it is usually connected to broncholiar disease. [7] If the wheezing is in the
inspiratory phase, it is an indicator of stiff stenosis whose causes range from tumours
to scarring. One of the main causes of wheezing is asthma, [7] other causes could be
pulmonary edema, interstitial lung disease and chronic bronchitis.
Pleural Rub:
Pleural Rub produces a creaking or brushing sound. These occur when the pleural
surfaces are inflamed and as a result rub against one another. They are heard during
both inspiratory and expiratory phases of the lung cycle and can be both continuous
and discontinuous. Pleural rub can suggest pneumothorax or pleural effusion.
.
Sounds:
Scattered Wet
Crackles
Sounds like:
typically
inspiratory
particularly wet
Caused by:
Excessive Fluid
Within the Lungs
Could be cause of:
Pneumonia
Other lung
infections
Crackles
Wheezes
Pleural Rub
sounding
Hair being rubbed
together or Velcro
opening
They are
discontinuous, nonmusical and brief
Usually heard on
expiration.
continuous,
high pitched,
hissing sounds
creaking or
brushing sounds.
Can be continuous
or discontinuous
Small airways open
during inspiration
and collapse during
expiration
ARDS
asthma
bronchiectasis
chronic bronchitis
consolidation
early CHF
interstitial lung
disease
pulmonary edema
forced airflow
Asthma
through abnormally CHF
collapsed airways
chronic bronchitis
with residual
COPD
trapping of air
pulmonary edema
pleural surfaces are pleural effusion
inflamed or
pneumothorax
roughened and rub
against each other
[1] Auscultation Assistant
[2] RL Wilkins, JR Dexter and JR Smith (1984). "Survey of adventitious lung sound
terminology in case reports". Chest 85: 523–525. doi:10.1378/chest.85.4.523.
http://chestjournal.org/cgi/content/abstract/85/4/523
[3] Lung and Infectious Diseases RL Wilkins, JR Dexter and JR Smith (1984).
"Survey of adventitious lung sound terminology in case reports". Chest 85: 523–525.
doi:10.1378/chest.85.4.523. http://chestjournal.org/cgi/content/abstract/85/4/523
[4] Forgacs P (1978). "The functional basis of pulmonary sounds" (PDF). Chest 73
(3): 399–405. doi:10.1378/chest.73.3.399. PMID 630938.
http://www.chestjournal.org/cgi/reprint/73/3/399.
[5] http://sprojects.mmi.mcgill.ca/mvs/RESP01.HTM#abnormalsounds
[6] ^ Shim CS, Williams MH (May 1983). "Relationship of wheezing to the severity of
obstruction in asthma". Arch Intern Med. 143 (5): 890–2. doi:10.1001/archinte.143.5.890.
PMID 6679232.
[7] ^ Baughman RP, Loudon RG (Nov 1984). "Quantitation of wheezing in acute asthma"
([dead link] – Scholar search). Chest 86 (5): 718–22. doi:10.1378/chest.86.5.718. PMID 6488909.
http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=6488909.