better to know that you have high blood pressure and to take tablets to control it than not know and suffer a stroke or something.
if you lose a fair amount of weight if you are very overweight,and do plenty of exercise, you can certainly reduce your blood pressure but probably not enough to stop taking medication to control it. in my experience, a change of diet, particularly the recommended reduction of salt in the diet, has very little effect on blood pressure. also, there are many people who are very slim, active and eat a healthy diet who still have high blood pressure.