6 Different Types of Breath Sounds

Breath sounds are the sounds that come from the lungs when a person breathes. They can be heard using a best stethoscope and even when a person breathes. These sounds can be normal or abnormal. Abnormal breath sounds occur when there is an underlying problem such as obstruction, infection, fluid in the lungs, asthma, and inflammation. The doctor checks the breath sounds with a stethoscope to diagnose an underlying medical condition.

1. Regular Breath Sounds

   A person’s lung is examined to note the frequency, intensity, and quality of the sounds. This helps in determining whether the sounds heard from the lungs are normal or abnormal.

   Breath sounds differ depending on where they occur from the respiratory system. These are classified as: ⁽¹⁾

   • Normal Lung or Vesicular Breath Sounds: These breath sounds can be heard over most of the chest with a stethoscope. The vesicular breath sounds occur when the air flows into and out of the lungs while breathing. It is soft, low-pitched, rustling in quality, and is continuous, intense, and high-pitched during inhalation and exhalation.
   • Bronchial Breath Sounds: This breath sound is audible over the trachea as the person breathes out and is loud, hollow, and high pitched. Hearing bronchial breath sound outside the trachea may indicate a health condition.
   • Normal Tracheal Breath Sound: This is heard over the trachea and is loud, harsh, and high pitched.

2. Wheezing

   Wheezing is a high-pitched, continuous sound that can be heard with or without a stethoscope. It is classified into 3 groups, which include: ⁽¹⁾

   • Monophonic Wheeze: It produces one note and is heard on inhalation and exhalation. It has a constant or varied frequency and may have a long duration or may occur during both phases of respiration.
   • Polyphonic Wheeze: It has multiple notes. Squeaks may occur during exhalation and can also increase at the end of exhalation.
   • Squawks: It is a brief wheeze occurring during exhalation.

   Wheeze is a result of blockage or constriction of the airway, which can occur in the following conditions:

   • Asthma
   • Tumors
   • Mucus build-up in airways
   • Chronic obstructive pulmonary disease
   • Obstruction of the airway by a foreign body

3. Crackling

   Crackles are intermittent sounds that are audible during inhalation and are similar to bubbling, popping, and clicking noises. It occurs when the small airways suddenly snap open and may indicate fluid inside a person’s lungs and they are not inflating properly.

   Conditions that cause cracking are:

   • Pneumonia
   • Chronic obstructive pulmonary disease
   • Pulmonary edema
   • Interstitial lung disease
   • Bronchitis
   • Heart failure

4. Rhonchi

   Rhonchi are the low-pitched, continuous sounds that are similar to snoring and occur due to blockages in the large airway of the lungs.⁽²⁾ It can occur during exhalation or during both exhalation and inhalation. Rhonchi occur due to the movement of fluid and other secretions in the airway. And can be due to asthma or viral infections in the upper respiratory system.

5. Stridor

   Stridor is a high-pitched sound that develops in the upper airway when a person inhales. ⁽²⁾ It is most audible in the neck. It occurs due to the obstruction in the upper respiratory tract. The sound occurs as the air passes through the narrowed area of the upper respiratory tract.

   Stridor can occur due to the following conditions:⁽¹⁾

   • Laryngomalacia: A soft and floppy larynx tissue in an infant
   • Vocal cord lesion
   • Tracheomalacia: A weakened and soft trachea of an infant
   • Bronchomalacia: Weakened cartilage in the bronchial tubes of an infant
   • Compression due to swelling or lesions

6. Pleural Rub

   A pleural rub is a squeaking, grating, or a rubbing sound that occurs due to inflamed pleural surfaces that rub against each other. Pleural surfaces are the membranes of the lungs that cover the lungs and help in respiration.

   A Pleural rub can occur due to the condition in which the pleura gets inflamed. These conditions include:⁽³⁾

   • Pneumonia
   • Pulmonary embolism
   • Malignant disease of the pleura

The treatment of the breath sounds depends on the cause and severity of the condition that is causing it. Mostly, antibiotics are prescribed and if there are inflammation involved anti-inflammatories may also be recommended. A long-term condition may require regular medication.

Anyone with an atypical breath sound should consult a doctor as a few abnormal breath sounds may indicate a serious health condition.