I've been having some episodes of really sharp pains in my left breast, though it may be my chest, I'm not sure how to really tell the difference (D cup) but I feel as if it's in my chest. Last night, the sharp pains would increase and began to run down the inside of my upper left arm, and occassionally shoot through to my back. Almost like if you were to draw a lightening bolt from my chest down the inside of my left arm, this is what I would imagine the pain path to be. They only last for about 2-5 seconds, but have been coming on more frequently of late. I'm not a healthy person, 36 years old, about 100 lbs over weight (as long as I can remember), high blood pressure (taking meds since I was 16), insulin resistent, not diabetic (yet), and hypothroidism. I've also been diagnosed in the past with a Mild Mitral Tricuspid Valve Regurgitation. I have arrhythmia and high blood pressure for which I take 50 mg atenolol twice a day. I also take Prevacid every day for GERD. Recently my Levothyroxin was upped from 175 to 200 mcg. I take 325mg aspirin daily, as well as a vitamin. I hesitate to go to the ER because the last time I went thinking it was my heart, it turned out to be that my dose of thyroid hormone was too high. Also, in the past couple of weeks that this has been ocurring, I have become EXTREMELY tired. Now believe me when I say I know tired, I KNOW tired. Having had hypothyroidism for years, I know tired. This tired is much worse, an extreme fatigue. I'm too tired to function, even though I have no other choice but to do so anyway (mother of 2 girls, 11 & 14). I haven't been sleeping good, but I feel like this tired is something completely different. I've had some "flutter" spells with my heart, not uncommon with me (for which I avoid caffeine). Also, occassionally will have the cold sweats and nausea, but having the stomach problems, I don't know what's what; however, have yet to have these with the chest pains. I'm not anemic, cholesterol is good, though my good cholesterol is very low, runs around 25 give or take a few. This is hereditary for my family, all have low LDL. Had lab work about a month ago and all was fine, but the pains have started since then. I haven't done anything out of the ordinary for me, like moving furniture, or throwing a ball, or coughing too hard, nothing I can think of that would cause it to be a pulled muscle, etc. It's just strange to me, and very worisome, that it's only my left side. Were it on both sides, I'd come more to believing in a pulled something. Also, if a woman's heart attack symptoms vary so much from a mans (which according to research they do), how are we supposed to know the difference in heart related issues, stomache issues, hormone imbalances, etc? Seeking advice and I'm thanking you in advance!