Which of the following is NOT a vital sign?

Urine output is considered a non-vital sign because vital signs typically refer to indicators that provide immediate and critical information about a person's physiological status. The four classic vital signs are heart rate, body temperature, respiratory rate, and blood pressure. Each of these plays a direct role in assessing a patient's immediate health and stability.

Heart rate indicates the efficiency of the heart’s pumping action and the overall cardiovascular health. Body temperature reflects the body’s ability to generate and dissipate heat, indicating potential infections or other health issues. Respiratory rate provides insight into respiratory function and oxygenation status.

Urine output, while important in evaluating a patient’s kidney function and overall fluid status, is not classified as a vital sign because it does not provide immediate and critical data about cardiovascular or respiratory function. Instead, it is considered a secondary measure in the assessment of a patient’s health.