The amount of radiation you are exposed to during a nuclear stress test is very small. It is not generally considered enough to increase your risk for cancer. If you are worried about direct exposure to radiation, know that the American Heart Association (AHA) and other organizations have created guidelines to help providers determine if the test is medically necessary. If your provider wants you to have the test, it means that the risk of cancer is outweighed by the benefit you'll gain from having a potential heart problem diagnosed through testing.