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Breath sounds

• Overview

Definition:

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

Alternative Names:

Lung sounds; Breathing sounds

Considerations:

The lung sounds can usually be heard with a stethoscope. This is called auscultation.

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

Absent or decreased sounds can mean:

• Reduced airflow to part of the lungs
• Over-inflation of a part of the lungs ( emphysema  can cause this)
• Air or fluid around the lungs
• Increased thickness of the chest wall

There are several types of abnormal breath sounds. The three most common are:

• Rales
• Rhonchi
• Wheezing

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

Rhonchi are sounds that resemble snoring. They occur when air through the large airways is blocked or becomes rough.

Wheezes are high-pitched sounds produced by narrowed airways. They often occurring when a person breathes out (exhales). Wheezing and other abnormal sounds can sometimes be heard without a stethoscope.

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 .

• Review Date: 2/14/2006
• Reviewed By: David A. Kaufman, M.D., Assistant Professor, Division of Pulmonary, CriticalCare & Sleep Medicine, Mount Sinai School of Medicine, New York, NY. Reviewprovided by VeriMed Healthcare Network.

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