Which of the following indicates a complete loss of consciousness?

Fainting, also known as syncope, indicates a complete loss of consciousness. This occurs when there is a temporary reduction in blood flow to the brain, often resulting in a brief episode where the person becomes unresponsive and falls over. The person typically regains consciousness within a few seconds to minutes once they are in a horizontal position or blood flow is restored.

In contrast, temporary confusion, fatigue, and dizziness do not imply a complete loss of consciousness. Temporary confusion can occur for various reasons, including disorientation or impaired cognitive function, but the person remains conscious and aware. Fatigue refers to extreme tiredness and can affect alertness but does not equate to a loss of consciousness. Dizziness, which may lead to feelings of lightheadedness or unsteadiness, is also a state where the individual remains aware and conscious. Thus, fainting is uniquely characterized by the total loss of awareness and responsiveness.