Respiratory sounds

Respiratory sounds, often referred to as breath sounds, are the noises produced by the structures of the lungs and airways during breathing. These sounds are significant in the assessment of respiratory health, as changes from normal patterns can indicate underlying pathologies.

Lungs diagram detailed

Types of Respiratory Sounds

• There are two primary types of normal breath sounds:
• Vesicular breath sounds: These are soft and low-pitched sounds heard throughout most of the lungs during inspiration and the first third of expiration. They are caused by air moving through smaller airways and into the alveoli^[1].
• Bronchial breath sounds: These are louder and higher-pitched sounds usually heard over the trachea and the area immediately surrounding it. They are prominent during both inspiration and expiration^[2].

Clinical Assessment

Respiratory sounds are typically assessed using a stethoscope in a systematic manner, covering all lung fields. The patient is usually asked to take deep breaths through the mouth. The clinician listens for the quality, intensity, and symmetry of breath sounds, and notes any additional or abnormal sounds^[3].

Pathological Breath Sounds

• Changes in normal breath sounds can indicate various respiratory conditions:
• Adventitious sounds: These are abnormal sounds that are superimposed on normal breath sounds. They include wheezes (high-pitched, musical sounds due to narrowed airways), rhonchi (low-pitched, continuous sounds often cleared by coughing), and crackles (short, discontinuous sounds often heard in heart failure, pneumonia, and fibrosis).
• Decreased or absent breath sounds: These may indicate severe airflow obstruction, lung collapse (atelectasis), or pleural effusion.
• Stridor: This is a harsh, high-pitched sound heard on inspiration, often due to upper airway obstruction.
• Pleural rub: This is a grating sound caused by the friction of inflamed pleural surfaces rubbing together, often heard in conditions like pleurisy^[4].

See also

• Pneumonia
• Asthma
• Chronic obstructive pulmonary disease
• Pleurisy
• Pleural effusion
• Atelectasis
• Stethoscope

References

Respiratory sounds Resources
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