Vital signs monitor the operation of the body's most basic functions, those being heart rate, respiration, body temperature, and blood pressure. Accuracy in measurement is important because in some cases even a small change or variation can indicate an existing problem or the building up of a problem. For instance, the relatively newly defined blood pressure state of prehypertension varies from normal blood pressure by as few as 1 to 2 points or as many as 10 points. Another example is that a chronically slightly elevated body temperature can indicate a problematic inflammation in the body somewhere. Factors that can influence vital signs are rest, exertion, infections, diet, physical position.