Which symptom may require the use of accessory muscles during respiration?

Using accessory muscles during respiration typically indicates that the body is experiencing an increased demand for oxygen. This can occur during physical exertion, respiratory distress, or conditions affecting lung function. When the primary muscles of respiration – the diaphragm and intercostal muscles – are insufficient to meet the body's oxygen demands, either due to effort (like during exercise) or respiratory impairment (like in asthma or COPD), the body compensates by engaging accessory muscles located in the neck, chest, and abdomen.

In contrast, situations like a normal resting state, calm relaxation, or effective breathing involve the body managing oxygen needs without added strain, allowing for a more efficient and smoother respiratory process. These conditions typically do not necessitate the recruitment of additional muscle groups for breathing.