What are the signs of cardiac arrest?

The signs of cardiac arrest include unresponsiveness, absence of breathing, and absence of a pulse. When a person experiences cardiac arrest, their heart stops functioning effectively, leading to a lack of blood flow to the brain and other vital organs. This results in the individual becoming unresponsive, as they are not receiving adequate blood flow. The absence of breathing indicates that the respiratory function has ceased due to the heart's inability to pump blood, which also affects oxygen supply to the body. Additionally, the absence of a pulse signifies that the heart is no longer generating effective contractions to circulate blood. Together, these three signs clearly identify a critical emergency requiring immediate intervention, such as cardiopulmonary resuscitation (CPR) or defibrillation.

In contrast, the other options provided describe symptoms or signs that may occur during various medical conditions but do not specifically indicate cardiac arrest. Chest pain, shortness of breath, and fatigue can be associated with many conditions, including angina or heart attack, yet they do not confirm cardiac arrest. Rapid heartbeat, dizziness, and sweating might present in cases of anxiety or other medical issues but are not definitive signs of a lack of cardiac activity. Lastly, fainting, confusion, and blurred vision can accompany numerous