One test doctors commonly use to diagnose coronary artery disease is an exercise stress test. An exercise stress test helps your doctor see how your heart works during exercise. This test is also called an exercise tolerance test, an exercise electrocardiogram or a treadmill test.

During the test, you will be connected to an electrocardiogram and a blood pressure cuff while you exercise. (If you aren't able to exercise, you can be given a drug that has the same effect on your body as exercise.)

A healthy person's electrocardiogram has a certain pattern. If the pattern of yours is different, doctors can tell if there is a problem with your heart.

Your blood pressure, pulse and heart's electrical activity are recorded before you begin exercising. During the test, you will be asked to walk on a treadmill or to ride a recumbant bike. Every couple of minutes, your doctor or the technician will increase the speed and slope of the treadmill (or the resistance on the bike). Your doctor or a technician will look for changes in the electrocardiogram patterns and blood pressure levels. These indicate whether your heart is getting enough oxygen.

Be sure to tell your doctor and the technician how you are feeling during the test. It is important to report any symptoms such as fatigue, nausea, difficulty breathing, chest pain, jaw or back discomfort, lightheadedness or dizziness, or physical inability to continue the test. At the end of the test, you may be asked to lie down or sit quietly.

The For Patients section has specific instructions for preparing for a stress test.