Blood Pressure Of 160/50 Blood Pressure?

Blood pressure? - blood pressure of 160/50

I go to the doctor today and told me that I have some high blood pressure we do not (know the exact number), and I realized I did not really know what blood pressure! I know that is the cause of obesity, poor diet, physical inactivity, etc. .. Why lower blood pressure? I've heard it has something to do with blood thinners? What two numbers? Any information would be a great help!