Basics of Lung Sounds

Crackles - Fine (Rales) Sounds

Fine crackles are brief, discontinuous, popping lung sounds that are high-pitched. Fine crackles are also similar to the sound of wood burning in a fireplace, or hook and loop fasteners being pulled apart or cellophane being crumpled.

Crackles, previously termed rales, can be heard in both phases of respiration. Early inspiratory and expiratory crackles are the hallmark of chronic bronchitis. Late inspiratory crackles may mean pneumonia, CHF, or atelectasis.

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The recommended auscultation position for the stethoscope is the Chest wall position. For this sound, use stethoscope's Diaphragm.

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The recommended patient position is Seated

Waveform

This waveform plots sound amplitude on the vertical axis against time on the horizontal axis.

Skin and Ribs

Blended View

Lungs

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Lessons

1	Vesicular - Normal
2	Crackles - Fine (Rales)
3	Crackles - Coarse (Rales)
4	Wheeze
5	Rhonchi - Low Pitched Wheezes
6	Bronchial
7	Pleural Rubs
8	Bronchovesicular

Practice Drill

Listening Tips
A synopsis of important sound features and timing for this abnormality.
Rales are brief, discontinuous, popping sounds that are high-pitched. Similar to wood burning in a fireplace. More commonly heard during inspiration.

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