Which of the following best describes the breath sounds commonly auscultated in cystic fibrosis?

• A. Crackles
• B. Wheezing
• C. Diminished breath sounds
• D. Normal breath sounds

Answer: (C)

In cystic fibrosis, thick mucus plugs the smaller airways and can cause partial obstruction and areas of atelectasis. When air can’t reach a portion of the lung effectively, the breath sounds from that region become quieter or diminished. This diminished airflow and reduced ventilation over affected regions is a common auscultatory finding in CF, making it the best description of what is typically heard.

You might also hear crackles or wheezes if secretions are present or if there’s partial bronchial irritation, but those sounds are not as consistently present as diminished breath sounds in areas with mucus plugging. Normal breath sounds would be less likely in someone with ongoing airway obstruction from CF.