Table of ContentsView AllTable of ContentsNormal SoundsWheezingStridorRhonchiRalesOther SoundsDiagnosis
Table of ContentsView All
View All
Table of Contents
Normal Sounds
Wheezing
Stridor
Rhonchi
Rales
Other Sounds
Diagnosis
There are normal breath sounds that your healthcare provider expects to hear. Abnormal breath sounds may indicate a respiratory illness, heart disease, infection, or other problems. The types of breath sounds—most commonly wheezing, stridor, rhonchi, or rales—can provide clues as to the underlying cause.
This article explains where breath sounds originate and what wheezing, stridor, rhonchi, and rales mean. It also describes possible causes and when it is time to seek medical care.
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Normal Breath Sounds
Auscultationis the process of listening with a stethoscope. With lung auscultation, your healthcare provider will listen for different sounds as you inhale, known as inspiration, and exhale, known as expiration.
As part of the evaluation, the provider will check for three types of normal breath sounds.
Tracheal Breath Sounds
Tracheal breath sounds are loud and high-pitched and are heard primarily over thetrachea(windpipe). The sounds are often described as being harsh as if air is being blown through a pipe.
Tracheal sounds are heard when the stethoscope is placed on the upper part of thesternum(breastbone) or between thescapulas(shoulder blades).
Bronchial Breath Sounds
The sounds are higher-pitched than those heard over other parts of the lungs. However, they are also quieter and more hollow-sounding than tracheal breath sounds.
Vesicular Breath Sounds
Vesicular breath sounds are sounds heard over the main body of the lungs. Vesicular breath sounds originate in the tiny air sacs of the lungs, calledalveoli. They produce soft, low-pitched sounds mainly during inspiration.
Vesicular breath sounds are best heard when the stethoscope is placed on either side of the spine beneath the scapula.
Wheezingdescribes whistling sounds that are usually more pronounced with expiration. These sounds may be “squeaky” (when high-pitched) or “moaning” (when low-pitched).
Wheezing may also be described as “musical” when there is a single note or multiple variable notes. Single notes suggest a disease in the smaller airways, while multiple notes suggest a disease in the larger airways.
“Squawks” may describe very short wheezes that usually occur late during inspiration.
There are many possible causes of wheezes. They include:
Stridorrefers to a high-pitched, continuous sound with a musical quality that is heard mostly with inspiration. It is typically loudest around the neck area and usually occurs when there is some sort of blockage in the upper airways.
Stridor should be assessed as a matter of urgency. In some cases, it may indicate a potentially life-threatening obstruction of the airways.
Causes of stridor include:
Stridor in any of these situations should be regarded as a sign of a medical emergency.
Rhonchi, in contrast to wheezes, cause low-pitched clunky or rattling sounds. They sometimes resemble snoring and will often clear with coughing.
Causes of rhonchi include:
Rales, also known as “crackles” orcrepitation,are rattling, crackling, clinking, or popping sounds that occur when collapsed alveoli suddenly snap open during inspirations. The sounds can come and go but are most pronounced when you inhale.
Crackles can be further described as “fine” or “coarse.” Fine crackles are related more to the small airways, while coarse crackles are related more to the large airways.
Potential causes of rales include:
Less Common Sounds
Wheezing, stridor, rhonchi, and rales are the most commonly heard breathing sounds, but there are other lung sounds aligned with specific diseases.
Whooping Cough
Whooping cough (pertussis)is an infectious respiratory disease that is less common than it used to be thanks to vaccines.But it does still affect children in the United States quite regularly.
Pleural Rub
A pleural rub, also known as a pleural friction rub, is a gritty sound that arises when the membranes lining the lungs, calledpleura, are inflamed and rub against each other. A pleural rub is likened to the sound of walking on fresh snow or sitting down on a leather couch.
A pleural rub may occur during both inhalation and exhalation. Unlike rales, the sound does not clear with coughing.
Conditions associated with a pleural rub include:
When to See a Healthcare Provider
Abnormal lung sounds that are persistent or worsening should be seen as a matter of urgency. In some cases, a specialist in respiratory diseases called apulmonologistmay be needed.
Lung Examination
In addition to auscultation, there are other components of thorough lung evaluation. These include a physical exam to check yourrespiratory rate, depth of breathing, pattern of breathing, and symmetry of your chest as you expand the lungs.
The healthcare provider may also percuss (tap) your chest and back. This helps determine if your lungs sound fluid-filled (such as with pneumonia) or hollow (such as with bronchiectasis). Any chest tenderness may be a sign of a fracture or a torn muscle or ligament.
Additional lab and imaging tests may be ordered, including:
Other Signs of Lung Disease
There are other things a healthcare provider would look for when investigating the cause of abnormal lung sounds. These include signs like:
When to Call 911
Summary
Abnormal lung sounds such as stridor, rhonchi, wheezes, and rales can provide important clues as to the cause of a respiratory illness. If an abnormal breathing sound is heard, your healthcare provider will look for other signs and order tests to help diagnose the underlying cause.
20 Sources
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Sarkar M, Madabhavi I, Niranjan N, Dogra M.Auscultation of the respiratory system.Ann Thorac Med. 2015;10(3):158. doi:10.4103/1817-1737.160831
Bohadana A, Izbicki G, Kraman SS.Fundamentals of lung auscultation.N Engl J Med. 2014;370(8):744-751. doi:10.1056/NEJMra1302901
Penzel T, Sabi AK.The use of tracheal sounds for the diagnosis of sleep apnoea.Breathe (Sheff).2017 Jun;13(2):e37–e45. doi:10.1183/20734735.008817
Henry B, Royston TJ.Localization of adventitious respiratory sounds.J Acoust Soc Am.2018 Mar;143(3):1297–1307. doi:10.1121/1.5025842
Open Resources for Nursing.Chapter 10 respiratory assessment. In:Nursing Skills [Internet] 2nd edition. Eau Claire (WI): Chippewa Valley Technical College; 2023.
MedlinePlus.Wheezing.
American College of Asthma, Allergy & Immunology.Wheezing, shortness of breath.
Patnaik S, Zacharias G, Jain MK, Samantaray KK, Sarapeneni SP.Etiology, clinical profile, evaluation, and management of stridor in children.Indian J Pediatr.2021;88(11):1115–1120. doi:10.1007/s12098-021-03722-8
Kim Y, Hyon Y, Jung SS, et al.Respiratory sound classification for crackles, wheezes, and rhonchi in the clinical field using deep learning.Sci Rep.2021;11:17186. doi:10.1038/s41598-021-96724-7
National Foundation for Infectious Diseases.Whooping cough (pertussis).
Centers for Disease Control and Prevention.Symptoms of whooping cough.
National Heart, Lung, and Blood Institute.Pleurisy and other pleural disorders.
Hayashi Y, Marumo S, Fukui M.Squamous cell carcinoma of the lung presenting unilateral thoracic hyperhidrosis: a case report and review of medical literature.Intern Med.2023 Jun 1;62(11):1635–1639. doi:10.2169/internalmedicine.0312-22
National Heart, Blood, and Lung Institute.Tests for lung disease.
Medline Plus.Clubbed fingers.
MedlinePlus.Nasal flaring.
MedlinePlus.Intercostal retractions.
MedlinePlus.Breathing difficulties - first aid.
Broaddus, V. Courtney.Murray and Nadels Textbook of Respiratory Medicine. Saunders.
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