M10.06.05 Normal and Abnormal Breath Sounds

Understanding breath sounds is pivotal in diagnosing respiratory conditions. This section elucidates the nuances of normal and abnormal breath sounds, essential for medical students’ clinical competence.

Normal Breath Sounds

Types of Normal Breath Sounds:

1. Vesicular Breath Sounds: Heard over peripheral lung fields during inspiration; characterized by soft, rustling quality.
2. Bronchial Breath Sounds: Heard over the trachea and main bronchi; characterized by loud, high-pitched sound with a short pause between inspiration and expiration.
3. Bronchovesicular Breath Sounds: Heard over the upper anterior chest and intercostal spaces; intermediate intensity and pitch between vesicular and bronchial sounds.

Location and Characteristics:

• Vesicular: Heard over peripheral lung fields; low-pitched, soft, and continuous.
• Bronchial: Heard over the trachea and main bronchi; high-pitched, loud, and brief.
• Bronchovesicular: Heard over the upper anterior chest and intercostal spaces; intermediate intensity and pitch.

Abnormal Breath Sounds

Types of Abnormal Breath Sounds:

1. Crackles (Rales): Discontinuous, popping sounds heard during inspiration or expiration; indicative of fluid-filled airways.
2. Wheezes (Rhonchi): Continuous, musical sounds heard during expiration; caused by narrowed airways.
3. Stridor: High-pitched, inspiratory sound heard over the upper airway; suggests upper airway obstruction.
4. Diminished Breath Sounds Reduced intensity or absence of breath sounds; indicative of lung collapse or pleural effusion.

Associated Conditions:

• Crackles: Pneumonia, pulmonary edema, bronchiectasis.
• Wheezes: Asthma, chronic obstructive pulmonary disease (COPD), bronchitis.
• Stridor: Croup, epiglottitis, foreign body aspiration.
• Diminished Breath Sounds Pneumothorax, pleural effusion, atelectasis.

Key Points to Remember

• Understand the characteristics and locations of normal breath sounds.
• Recognize abnormal breath sounds and their associated conditions for accurate diagnosis.
• Utilize auscultation skills alongside patient history and other clinical findings for comprehensive assessment.

Bibliography

1. Bates, B., & Dains, J. E. (2018). Bates’ Guide to Physical Examination and History Taking. Wolters Kluwer.
2. Macleod, J., & Mathew, R. (2015). Clinical Examination: A Systematic Guide to Physical Diagnosis. Elsevier Health Sciences.
3. Swartz, M. H. (2019). Textbook of Physical Diagnosis: History and Examination. Elsevier.