Which symptom may indicate a casualty is in shock?

Rapid breathing is an indication that the body is attempting to compensate for reduced blood flow and oxygen delivery, which are common in a state of shock. When a person is in shock, their body reacts to diminished circulation and organ perfusion by increasing respiratory rate to enhance oxygen intake. This physiological response occurs as the body tries to maintain adequate oxygen levels to vital organs, signaling a potential life-threatening condition that requires immediate medical attention.