What condition is characterized by a cessation of breathing?

The condition characterized by a cessation of breathing is respiratory arrest. This occurs when an individual stops breathing entirely, which can be a critical medical emergency because it leads to a lack of oxygen supply to the body, potentially resulting in brain damage or death if not promptly addressed. Respiratory arrest can be caused by various factors, including trauma, obstruction, or underlying medical conditions.

In the context of the other choices, while hyperventilation involves rapid or excessive breathing, it does not equate to stopping breathing altogether. Aspiration pneumonia refers to an infection caused by inhaling food, liquid, or vomit into the lungs, rather than a halt in breathing. Hypoxemia describes low levels of oxygen in the blood, which can occur due to various respiratory issues but does not specifically indicate the absence of breathing. Thus, the definition and implications of respiratory arrest distinctly identify it as the correct answer.