Breath Sounds

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 health care provider may hear normal breathing sounds, decreased or absent breath sounds, and abnormal breath sounds.

Absent or decreased sounds can mean:

• Air or fluid in or around the lungs (such as pneumonia, heart failure, and 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 four most common are:

1. Rales. Small clicking, bubbling, or rattling sounds in the lungs. They are heard when a person breathes in (inhales). They are believed to occur when air opens closed air spaces. Rales can be further described as moist, dry, fine, and course.
2. Rhonchi. Sounds that resemble snoring. They occur when air is blocked or air flow becomes rough through the large airways.
3. Stridor. Wheeze-like sound heard when a person breathes. Usually it is due to a blockage of airflow in the windpipe (trachea) or in the back of the throat.
4. Wheezing. High-pitched sounds produced by narrowed airways. They are most often heard when a person breathes out (exhales). Wheezing and other abnormal sounds can sometimes be heard without a stethoscope.