A constellation of clinical signs that indicate an increased effort to maintain oxygenation and ventilation due to an underlying respiratory pathology (e.g., asthma). Signs of increased work of breathing include accessory muscle use (e.g., sternocleidomastoid and scalene muscles), tripod positioning, nasal flaring, retractions (intercostal, subcostal, and suprasternal), grunting, pursed lips, and paradoxical breathing.