Which vital sign measurement can indicate an infection?

An elevated body temperature, commonly referred to as a fever, is a critical indicator that can signal the presence of an infection in the body. When the immune system detects foreign pathogens like bacteria or viruses, it responds by raising the body temperature to create an environment less favorable for these invaders and to enhance the immune response. This physiological reaction is part of the body's defense mechanism, as higher temperatures can inhibit pathogen growth and improve the efficacy of immune cells.

While changes in heart rate, blood pressure, and respiratory rate can also reflect the body’s response to various conditions, including infections, an elevated body temperature is more directly associated with the presence of infection itself. For example, an increased heart rate could occur due to many factors such as stress, exercise, or dehydration, while changes in blood pressure and respiratory rate can be influenced by various medical conditions unrelated to infections. Therefore, when evaluating vital sign measurements for signs of infection, fever stands out as a significant and specific indicator.