With MINIMAL exertion, I feel my heartbeat in my temples, cannot catch my breath, feel near fainting. This will occur after 30-60 seconds worth of vigorous activity. Yes, I have eaten beforehand. I'm 5'6" , 130lbs. but am VERY sedentary. Prone to migraines from exercise (and from other causes) so tend to avoid. I'm 31 yr old female, these recent episodes have really been frightening...cannot breathe, tightness in chest, tunnel vision, etc. No history of asthma, per se, except asthmatic bronchitis when sick with cold. No recurrence of that since I stopped smoking 2+ yrs. ago. Pretty sure this is linked to extreme laziness, but would like advice/confirmation. Thanks.