A treadmill stress test allows one's physician to see how well the heart deals with exertion. As one's body works harder, it requires more fuel and the heart pumps more blood. This test indicates any lack of blood supply through the arteries that go to the heart. The test monitors heart rate, beathing, blood pressure, EKG and exhaustion levels.
There is no more discomfort or risk involved with this test than there is with general walking or jogging, and physicians and medical professionals are on hand throught the examination.