<s>[INST] Hi,  My mum started getting chest pain that radiates to her back about a month ago. Since a few days ago, these episodes have increased in frequency and at the same time she felt very lethagic, weak and she became pale. We took her to the ER at the hospital immediately and all the blood tests, cardiographs and x-rays came back normal. She is about to have a stress test (on the treadmill). What can this possibly reveal if all the other tests were normal? Does it sound like she has a heart problem? [/INST] Thanks for your question on Chat Doctor. I can understand your concern. Yes, her symptoms can be seen in heart diseases. Sometimes resting ECG is normal despite having heart diseases like coronary artery disease (CAD). So stress test (trade mill test) is indicated. Stress test is non-invasive test used for the screening of CAD. It shows how our heart functions under stress (trade mill running). This will also tell about fluctuations in heart rate and blood pressure. So get done stress test. If this is normal then no need to worry about heart diseases. Hope I have solved your query. I will be happy to help you further. Wishing good health to your mother. Thanks. </s>