An exercise stress test is a screening tool used to evaluate coronary artery disease.  Exercise stress tests are performed to determine the amount of stress that your heart can manage before developing either an abnormal rhythm or evidence of ischemia (not enough blood flow to the heart muscle).  This is done by walking on a treadmill while your heart rate and blood pressure are monitored.

Reasons why a stress test may be ordered:

• You are having chest pain
• Your chest pain/discomfort is becoming more severe or is occurring more often
• You have had a heart attack
• You are going to start an exercise program and you have heart disease or certain risk factors, such as diabetes
• To identify heart rhythm changes that may occur during exercise
• To evaluate the significance of a heart valve problem

If the stress test is abnormal, further testing may be necessary such as a nuclear stress test or a stress echocardiogram.

Source:  http://www.nlm.nih.gov/medlineplus