I don t know if I am having a heart attack. I read about the systems, but I don t know if any pertain to what I m feeling. I feel hot at times but it could be hot flashes which I suffer a lot of times during the day. My fear is I feel like I m getting a headache today, felt nauseous yesterday night and tonight , my left upper arm feels like I did a lot of exercise, a little pressure about my breast, light headedness, and a little pain between my shoulder blades. what do you think?