###Human: What causes warmness in the left side of chest? ###Assistant: Hello. This kind of chest pain occurs during stress and anxiety only. We label them nonspecific cardiac chest pain. But, we should always keep in consideration cardiac chest pain and acid reflux. It is important to differentiate between the all. However, the cardiac chest pain is severe and crushing in nature. It increases on activity like walking and exercising. It also gets radiated to left arm. Since your ECG and other cardiac workup are normal, the pain is not due to cardiac issues. For acid reflux, I would advise you to take a combination of Pantoprazole and Domperidone once a day. Your increase in heart rate might be possibly because of anxiety only. For anxiety, try to do meditation and if no relief, you would be treated with anti-anxiety drugs like Etizolam. For further clarifications consult a cardiologist online -->