I am a 36 year old female. I am about 60 lbs overweight, and am currently going to the gym/dieting. Recently, I have been feeling heaviness in my arm and been a little light headed. This happens sporatically. I could be sitting at my desk, in bed, etc. I went to the emergency room at one point... They did an EKG, a CTScan of my head and took blood work, but didn't show anything. Do I need to be concerned?