Which of the following is NOT a vital sign?

Vital signs are key indicators of a person's essential bodily functions and help healthcare providers assess a patient's health status. The primary vital signs traditionally include blood pressure, heart rate, respiratory rate, and body temperature. Each of these plays a critical role in evaluating a patient's physiological condition and responses.

Temperature fluctuation, while it can indicate changes in a person's health, is not considered a vital sign in itself. Instead, a specific measurement of body temperature, such as the temperature taken at a single point in time (e.g., using a thermometer), would be classified as a vital sign. Fluctuations refer to variations or changes in temperature rather than a specific measurement, which is why it does not fit the definition of a vital sign.

In contrast, blood pressure, heart rate, and respiratory rate are direct measurements that provide a snapshot of important aspects of a patient’s cardiovascular and respiratory health, thus qualifying them as vital signs.