Respiratory sounds

Types

There are at least three kind of respiratory sound

1. Rhonchi
2. Rales / crackles
3. Stridor

Rhonchi

• It is a low-pitched sound that usually starts in the larger airways in the lungs.
• It can be heard on an inhalation or exhalation, and it’s often compared to the sound of snoring.
• These sounds are produced when there is something blocking the airway, like fluid.

Rales / crackles

• Rales are a higher-pitched sound sometimes called crackles or bibasilar crackles.
• These sounds are formed when air moves into closed spaces. This usually occurs in the smaller parts of the lungs, like the alveoli.
• These are tiny sacs of air and inflate and deflate with each breath. When these tiny sacs are damaged or weighed down with fluid or mucus, they can make a crackling sound as they attempt to fill with air.

Related entities

Both Rhonchi and Rales:

• Pneumonia
• Bronchitis
• COPD

Rales

• Pulmonary edema
• Interstitial pneumonitis
• Asthma
• Heart failure

Rhonchi

• Cystic fibrosis
• Chronic obstructive pulmonary disease (COPD)
• Bronchiectasis

Stridor

• It is a high-pitched extra-thoracic breath sound resulting from turbulent air flow in the larynx or lower in the bronchial tree.
• It is a physical sign which is caused by a narrowed or obstructed airway.
• It can be inspiratory, expiratory or biphasic, although it is usually heard during inspiration.
• Inspiratory stridor often occurs in children with croup.
• It may be indicative of
  • Epiglottitis or Subglottic stenosis
  • Foreign body lodged in the airway
  • Laryngeal tumor
  • Laryngospasm (from Aspiration, GERD)
  • Thyroiditis such as Riedel's thyroiditis
  • Vocal cord palsy
  • Vasculitis
  • Infectious mononucleosis