A stress test is an assessment of someone’s physiological or aerobic reserve, and a fairly good assessment of a person’s hemodynamic and circulatory response to exercise. The most common algorithm that’s used on a treadmill is something called the BRUCE protocol. The test assesses your fitness level, and the health of the circulatory system, and looks for problems with plugged arteries or atherosclerosis.
The treadmill examination doesn’t allow healthcare providers to look at the arteries themselves but infers a problem with the arteries. Because of this limitation, treadmill examinations can be wrong, and there is up to a one-third chance of a false positive.