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Breath sounds

Alternative names

Lung sounds; Breathing sounds


Breath sounds are the sounds produced by the structures of the lungs during breathing.


The lung sounds are usually examined by auscultation (listening) with a stethoscope.

Normal lung sounds occur in all parts of the chest area, including above the collarbones and at the bottom of the rib cage. Auscultation may find normal breath sounds, decreased or absent breath sounds, and abnormal breath sounds.

Absent or decreased sounds reflect reduced airflow to a portion of the lungs, over-inflation of a portion of the lungs (such as with emphysema ), air or fluid around the lungs, or increased thickness of the chest wall.

There are several types of abnormal breath sounds: rales, rhonchi, and wheezes are the most common. Wheezing can sometimes be heard without a stethoscope, and other abnormal sounds are sometimes also loud enough to be detected with the unaided ear.

Rales (crackles or crepitations) are small clicking, bubbling, or rattling sounds in the lung. They are believed to occur when air opens closed alveoli (air spaces). Rales may be further described as moist, dry, fine, and coarse.

Rhonchi are sounds that resemble snoring. They are produced when air movement through the large airways is obstructed or turbulent.

Wheezes are high-pitched, musical sounds produced by narrowed airways, often occurring during expiration (breathing out).

Common Causes

  • Foreign body obstruction of the airway
  • Emphysema
  • Asthma
  • Pulmonary edema
  • Bronchiectasis
  • Chronic bronchitis
  • Acute bronchitis
  • Interstitial lung disease
  • Pneumonia
  • Tracheobronchitis
Note: See also wheezing .

Home Care

Health care measures that can be employed at home depend on the disease causing any abnormal breath sounds. Consult with your health care provider.

Call your health care provider if

  • Difficulty breathing or shortness of breath -- a potential emergency condition!
  • Use of accessory muscles or other signs of increased breathing work such as retractions, nasal flaring , and cyanosis -- this is an emergency symptom!
  • Wheezing or other abnormal sounds, persistent or noticed for the first time

The medical history will be obtained and a physical examination performed.

Medical history questions documenting an abnormal lung sound in detail may include:
  • Time pattern
    • When did it start?
    • How long did it last?
    • Is there a pattern to the occurrences?
  • Quality
    • How would you describe it?
  • Relieving factors
    • What makes it better?
  • Aggravating factors
    • What makes it worse?
  • Other
    • What other symptoms are also present?
    • Is there any coughing?
    • Is there any difficulty breathing?
Note: Abnormal breath sounds are usually discovered by the health care provider, and the affected person may or may not have been aware of its presence.

The physical examination will include careful assessment of the lungs and breathing.

Diagnostic tests that may be performed include:
  • Chest x-ray
  • Pulmonary function tests
  • Blood tests (including an arterial blood gas)
  • CAT scan of the chest
  • Analysis of a sputum sample ( sputum culture , sputum gram stain )

Treatment will depend on the disease that is causing the abnormal breath sounds.

After seeing your health care provider:
You may want to add a diagnosis related to abnormal breath sounds to your personal medical record.

Update Date: 1/27/2004

Allen J. Blaivas, D.O., Division of Pulmonary, Critical Care, and Sleep Medicine, University Hospital, Newark, NJ. Review provided by VeriMed Healthcare Network.

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Last updated: Tue, 06 Jan 2009 00:20:03 GMT