Breath sounds

Definition

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

See also: Wheezing

Alternative Names

Lung sounds; Breathing sounds

Considerations

The lung sounds are best 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:

• Air or fluid in or around the lungs (pneumonia, heart failure, pleural effusion)
• Increased thickness of the chest wall
• Over-inflation of a part of the lungs (emphysema can cause this)
• Reduced airflow to part of the lungs

There are several types of abnormal breath sounds. The 4 most common are:

• Rales
• Rhonchi
• Stridor
• Wheezing

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

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

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

Stridor is a wheeze-like sound heard when a person breathes out (exhales). Usually it is due to a blockage of airflow in the windpipe (trachea) or in the back of the throat.

Common Causes

• Acute bronchitis
• Asthma
• Bronchiectasis
• Chronic bronchitis
• Emphysema
• Interstitial lung disease
• Foreign body obstruction of the airway
• Pneumonia
• Pulmonary edema
• Tracheobronchitis

Call your health care provider if

Nasal flaring and cyanosis are emergency symptoms. Difficulty breathing or shortness of breath can be an emergency condition. Seek immediate medical care if you have any of these symptoms.

Contact your health care provider if you have wheezing or other abnormal breathing sounds.

See also: Breathing difficulty

What to expect at your health care provider's office

Your health care provider will do a physical exam and ask you questions about your medical history and your breathing.

Questions may include:

• When did the breathing sound start?
• How long did it last?
• How would you describe your breathing?
• What makes it better or worse?
• What other symptoms do you have?

The health care provider usually discovers abnormal breath sounds. You may not even notice them.

The following tests may be done:

• Analysis of a sputum sample (sputum culture, sputum gram stain)
• Blood tests (including an arterial blood gas)
• Chest x-ray
• CT scan of the chest
• Pulmonary function tests