Aletam

hello i am 19 well i will be 20 in a couple weeks but i just went to the doctor today because i was having some anxiety issues but while i was there and they checked my blood pressure it came back that it was 138/72 i was not too concerned because it had been this way the time before and the doctor said it was just fine. then he came in to day and made me feel like it was horrible because my blood pressure has been like this for 2 years now. i am kind of upset because this is the first time anyone has said anything to me about my blood pressure and it has been this way for two years? anyways i am starting on a dieretic tomorrow in hopes that it will work. i formed high blood pressure when i was pregnant and it never totally went down.....the doctor has taken blood tests since my blood pressure was this way and said there was no reason to believe that it was due to kidney problems. my grandmother has been on blood pressure medicine since her 20's and my father has congestive heart failure and high blood pressure. so my question is is it normal for someone of my age to have this blood pressure? is it just precautionary that my doctor would be putting me on the medicine? should i be worried?
p.s. i am also overweight but he said nothing to me about losing weight andexercising although i plan to but i find it weird he just perscribed medicine "due to new regulations" in his words...pretty much 5 years ago i would have been considered fine he said