What is the first symptom to check for in an ill or injured passenger according to the symptom sequence?

In assessing an ill or injured passenger, the first symptom to check for is the stoppage of breath. This is critical as the airway and breathing are essential for survival. If a passenger is not breathing, immediate action must be taken to restore their breathing or provide emergency assistance. Recognizing that a person is not breathing allows flight attendants to initiate life-saving measures such as administering CPR or using an Automated External Defibrillator (AED) if necessary.

While severe bleeding, no pulse, and shock are also important symptoms to monitor, they typically come into play after confirming the passenger's ability to breathe. For instance, severe bleeding must be managed quickly as well, but it follows the priority of ensuring that the passenger can breathe. Similarly, the absence of a pulse indicates a critical condition, but recognizing and addressing the issue of breathing takes precedence in the emergency response protocol. Shock is a later symptom of distress that may result from various conditions, including severe bleeding or cessation of breathing, but it does not take priority over assessing breath first.