From the homeostatic point of view, stress can be defined as a state of physical, mental, or emotional alteration that moves an organism away from its normal state of equilibrium. The scope of the modern exercise stress test is broad. It is designed to evaluate the integrated performance of the patient’s cardiovascular system, pulmonary organs, endocrine system, and heat-controlling mechanisms at the limits of exercise. By measuring the ability of these physiology processes to meet the metabolic demands of exercise, clinicians can assess the patient’s health better.