In a stress test, you walk on a treadmill that makes your heart work progressively harder. An electrocardiogram (ECG) monitors your heart's electrical rhythms. The doctor also measures your blood pressure and monitors whether you have symptoms like chest discomfort or fatigue. Abnormalities in blood pressure, heart rate, or ECG or worsening physical symptoms could point to coronary artery disease (CAD): fatty deposits (plaques) that reduce the flow of oxygen-rich blood to the heart muscle.
A treadmill exercise stress test is used to determine the effects of exercise on the heart. Exercise allows doctors to detect abnormal heart rhythms (arrhythmias) and diagnose the presence or absence of coronary artery disease.