Is a stress test risky or uncomfortable?

The risk of something serious happening during a stress test—a heart attack, for example—is very small (about one in 5,000). The risk of major complications is generally dependent on the seriousness of your heart to start. Stress testing laboratories take several precautions to make sure you are safe. First, your doctor reviews your medical condition to make sure a stress test is appropriate. During the stress test, a technician is always in the room, your heart rate and blood pressure are closely monitored, and equipment and medications needed to handle an emergency are nearby.

Still, unless you are in prime physical condition, you should be prepared to experience some discomfort during the test, just as you would if you were jogging or doing some other kind of vigorous exercise. For example, you may feel fatigued or moderately short of breath, or experience muscle cramps.

In addition, the blood pressure can sometimes drop too low during a stress test. If that happens, you may feel dizzy or faint. Some people develop chest pain, shortness of breath or an abnormal heart rhythm during stress testing. In each of these cases, you should alert the technician so the stress test can be stopped. These problems typically go away once you stop exercising, but you may need further treatment if they persist.

If you are given a medication to make the heart beat faster and harder because you cannot exercise vigorously, you may feel jittery or uncomfortable until the medication wears off, possibly for a few hours. Some of these medications can cause wheezing, shortness of breath and other asthma-like symptoms, which may require treatment.