question: Hi Im a 36 year old male and have experienced problems with physical activity for example yesterday I was gardening 1 - 3 hrs quiet vigoursly at this point I started to fell lightheaded and slightly weightless. I came in dooors and took my BP is was 176/91 with a pulse of 105.  After an hour it came down to 140/80 pulse of 69.  However this leaves me absolutely shattered I slept 12 hours got up and returned to bed after breakfast and a short walk in the sun for another 2 hrs.  This espisode has happen on serveral occassions.  I weight 300lbs and recently been 30mg of Citalopram (18mths) but have ceased during a controled period, My wife says that Im in a better place now.  However this is knocking my confidence I have recently returnd to my GP and after serveral blood tests says there is nothinh wrong.  Can you offer any advice.