Past week, I have had shortness of breath, pounding heart beat, dizzy spells, blurry eyesight and headaches. I am under no sort of stress, I have had a pounding heart before which would only last a fee minutes to an hour but for two-three days it has been continuous. Also, last night while I was having shortness of breath, dizzy and blurry vision, I felt very exhausted (I have been feeling constantly tired for a week) and my fingers, arms, everything, just turned all tingly. Why is this?