Which of the following is an indicator of abnormal respiratory function?

Shortness of breath (SOB) is an important clinical indicator of abnormal respiratory function. It reflects the body's struggle to maintain adequate gas exchange and oxygenation, which could signal underlying respiratory or cardiovascular issues. When a patient experiences SOB, it can indicate that the lungs are not efficiently delivering oxygen to the bloodstream or that there is difficulty in removing carbon dioxide, potentially stemming from conditions such as asthma, chronic obstructive pulmonary disease (COPD), pneumonia, or heart failure.

In contrast, normal breath sounds typically indicate that there is no obstruction or major issues with airflow in the lungs, and steady oxygen saturation above 95% suggests adequate oxygenation and functional respiratory status. Additionally, utilizing the diaphragm for breathing is a normal physiological process, as it is the primary muscle used in inhalation. Therefore, the presence of SOB is a clear sign of abnormal respiratory function and warrants further evaluation and intervention.