In one sentenceIn bronchiectasis, sound comes from dilated airways filled with secretions. This gives a coarse pattern that starts early and may change with coughing.
- Typical pattern: early to mid-inspiratory, loud, low-pitched coarse crackles, often with rhonchi.
- The sound may change after coughing or airway clearance.
- The distribution follows the anatomical spread of the disease: regional or widespread.
Yes. In wide airways filled with secretions, fluid bridges break and the secretions vibrate with the flow.
Not the main change.
Not the main change.
Early and mid-inspiratory coarse crackles and rhonchi. They change with coughing.
For the reasoning: Where does sound come from? · How does sound reach the chest wall? · How do adventitious sounds arise? · From sound to differential diagnosis
What do you hear?
You hear loud, low-pitched, bubbling crackles that start at the beginning or middle of inspiration. Rhonchi or a low-pitched wheeze may accompany them in expiration. The findings may be confined to one lobe or be widespread.
Why does it sound like this?
The crackles arise in larger airways that are rich in secretions. As air passes through the fluid, liquid bridges break and bubbles burst. These events produce longer and lower-pitched waves than fine crackles.
Distinguishing clues
- Cough test: Ask the patient to cough a few times, or listen again after airway clearance. Sounds from secretions move or decrease.
- Timing: Early to mid-inspiratory. In fibrosis, crackles are late inspiratory and change little with coughing.
- Rhonchi: Rhonchi that change with coughing support mobile secretions. A rhonchus that persists at the same site suggests a fixed narrowing or another fixed source.
Pitfalls
- Similar sounds are heard in cystic fibrosis, chronic suppurative airway disease and pneumonia. The sound shows airway mechanics and secretions. It does not make the diagnosis.
- If infection develops, focal bronchial breathing may be added to the background of coarse sounds. Do not miss this new finding.
Next step
Request HRCT and sputum culture. Listen at the same point before and after airway clearance. This comparison is also useful during follow-up.
Try this pattern in a case
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A reliable sound for serial monitoring
In patients with cystic fibrosis and bronchiectasis, crackle timing and waveform measured in a clinical setting showed good test–retest reliability. This supports objective monitoring. Even so, the sound is a marker of airway mechanics and secretions rather than a diagnosis.
The acoustics of secretions
Measurements in airways containing secretions showed that breath sound power was redistributed. When the secretions were removed by suction, these spectral changes decreased. This supports a real acoustic contribution from airway fluid. It does not prove that every rhonchus arises from a single meniscus or bubble mechanism.
The term rhonchus
In a series of 304 patients with bronchiectasis, rhonchi were a familiar examination finding, together with crackles and a productive cough. Historically, clinicians have used the term inconsistently, sometimes for both continuous and discontinuous sounds. In your notes, also record pitch, phase, site and response to coughing.
Real recordings
The spectrogram of a bronchiectasis recording selected from the public ICBHI database shows coarse transient events. Single examples show how clinical features look within noise. Do not read them as disease-specific templates.
See the reference list for sources.