A stress test, sometimes called a treadmill test or exercise test, helps a doctor find out how well your heart handles work. As your body works harder during the test, it requires more oxygen, so the heart must pump more blood. The test can show if the blood supply is reduced in the arteries that supply the heart. It also helps doctors know the kind and level of exercise appropriate for a patient.

A person taking the test:
is hooked up to the equipment to monitor the heart.
walks slowly in place on a treadmill. Then the speed is increased for a faster pace and the treadmill is tilted    to produce the effect of going up a small hill.
may be asked to breathe into a tube for a couple of minutes.
can stop the test at any time if needed.
afterwards will sit or lie down to have their heart and blood pressure checked.

Heart rate, breathing, blood pressure, electrocardiogram (ECG or EKG), and how tired you feel are monitored during the test.

Healthy people who take the test are at very little risk. It's about the same as if they walk fast or jog up a big hill. Medical professionals should be present in case something unusual happens during the test.

A physician may recommend an exercise stress test to:
Diagnose coronary artery disease
Diagnose a possible heart-related cause of symptoms such as chest pain, shortness of breath or    lightheadedness
Determine a safe level of exercise
Check the effectiveness of procedures done to improve coronary artery circulation in patients with coronary    artery disease
Predict risk of dangerous heart-related conditions such as a heart attack.

Depending on the results of the exercise stress test, the physician may recommend more tests such as a nuclear stress test or cardiac catheterization.