Why do you get tachycardia with an infection?

Tachycardia during an infection occurs as part of the body's immune response. When an infection is present, the body releases inflammatory cytokines and other mediators, which can stimulate the heart to beat faster in an effort to increase blood flow and deliver more oxygen to tissues. Additionally, fever, a common response to infection, raises metabolic demands and can further contribute to an elevated heart rate. This increased heart rate helps the body fight off the infection more effectively.