Which of the following is NOT a vital sign?

Cholesterol level is not classified as a vital sign. Vital signs are measurements that provide critical information about a person's essential bodily functions and health at a given moment. They typically include respiration rate, which indicates how many breaths a person takes per minute; temperature, which reflects the body's ability to generate and lose heat; and pulse rate, which measures the heart rate and how often the heart beats per minute. These parameters are routinely assessed by healthcare professionals to monitor a patient’s physiological status and detect any potential health issues quickly.

In contrast, cholesterol level is a laboratory measurement that reflects the amount of cholesterol in the blood, which is important for assessing cardiovascular health but does not provide immediate information about vital physiological processes. It is evaluated through blood tests rather than being a direct measure of a person's current health status in the way that the other vital signs are.