During your assessment of a patient with respiratory distress, you hear wheezing when listening to breath sounds. This indicates:

Wheezing during breath sounds is primarily associated with lower airway obstructions. This characteristic noise arises when air passes through narrowed airways, which can occur due to conditions such as asthma, bronchitis, or COPD (chronic obstructive pulmonary disease). The sound is a result of turbulent airflow in the bronchi and bronchioles, indicating that the air passages are constricted or obstructed, leading to difficulty in breathing.

The other options imply different respiratory problems: fluid in the alveoli typically manifests as crackles rather than wheezes; swelling of the upper airway would produce stridor, a high-pitched sound; and secretions present in the airway generally lead to gurgling or rattling sounds, rather than wheezing. Thus, the presence of wheezing specifically points to a lower airway obstruction, confirming why this choice is the correct answer.