From the Guidelines
During auscultation of the lungs, you can hear several types of breath sounds, including normal sounds like vesicular, bronchial, and bronchovesicular sounds, as well as abnormal sounds like crackles, wheezes, rhonchi, pleural friction rubs, stridor, and squeaks, with the latter being more suggestive of fibrotic hypersensitivity pneumonitis 1. When evaluating lung sounds, it's essential to consider the clinical context and underlying respiratory conditions. Abnormal breath sounds can indicate various conditions, such as fluid or mucus in airways, narrowed airways, secretions in larger airways, or inflamed pleural surfaces.
- Normal breath sounds include:
- Vesicular sounds: soft, low-pitched sounds heard over most lung fields
- Bronchial sounds: loud, high-pitched, hollow sounds heard over the trachea
- Bronchovesicular sounds: intermediate sounds heard near major bronchi
- Abnormal breath sounds include:
- Crackles: fine or coarse crackling sounds from fluid or mucus in airways, commonly heard in conditions like idiopathic pulmonary fibrosis 1
- Wheezes: continuous, high-pitched musical sounds from narrowed airways
- Rhonchi: low-pitched, snoring-like sounds from secretions in larger airways, which can be heard in conditions like nontuberculous mycobacterial diseases 1
- Pleural friction rubs: creaking sounds from inflamed pleural surfaces
- Stridor: harsh, high-pitched sound from upper airway obstruction
- Squeaks: high-pitched sounds, which are more suggestive of fibrotic hypersensitivity pneumonitis 1 Diminished or absent breath sounds may indicate conditions like pneumothorax, pleural effusion, or severe COPD. When auscultating, it's crucial to systematically compare both lungs, listening during both inspiration and expiration, and ask patients to breathe deeply through their mouth. The location, timing, and quality of these sounds provide valuable diagnostic information about underlying respiratory conditions.
From the Research
Lung Sounds During Auscultation
There are various types of lung sounds that can be heard during auscultation, including:
- Wheezes: high-pitched sounds typically associated with asthma or chronic obstructive pulmonary disease (COPD) 2, 3
- Rhonchi: low-pitched sounds often related to secretions or obstruction in the airways
- Crackles: high-pitched sounds usually indicating an abnormality in the lung tissue, such as inflammation or fluid buildup
- Stridor: a high-pitched sound typically associated with an obstruction in the upper airways
Obstructive Lung Diseases
Obstructive lung diseases, including asthma and COPD, can result in significant morbidity and mortality 4. These diseases often exhibit similar symptoms, such as wheezing and shortness of breath, but have distinct differences in etiology, symptoms, and response to therapy 2, 3.
Gas Exchange Abnormalities
Gas exchange abnormalities, including ventilation-perfusion inequality, can lead to hypoxemia and hypercapnia in lung diseases 5. Understanding these mechanisms is crucial for developing effective treatments and improving patient outcomes.
Chronic Lung Diseases
Chronic lung diseases, including COPD, asthma, and interstitial lung diseases, are a significant public health concern, with complex interactions between environmental factors, multimorbidity, and health disparities 6. Recognizing the importance of these diseases and prioritizing research is essential for improving global patient outcomes.