Crackles are described as:

• A. Crushing tissue like sounds
• B. Dry, lack of breath sounds
• C. Continuous wheezing
• D. Straining of chest muscles

Answer: (A)

Crackles are discontinuous, crackling or popping sounds heard during inspiration, produced when small airways and alveoli suddenly open after being collapsed or when air moves through fluid-filled airways. This crisp, tissue-crumpling sensation is why crackles are often described as a crackling or crunching sound. They are not dry, absent breath sounds (which indicate little or no airflow), nor continuous wheezes (which are musical and ongoing), nor a sign of chest-muscle straining. Crackles can point to conditions that involve fluid in the lungs or partial collapse of airways, such as atelectasis, pneumonia, or congestive heart failure.