In my own case, I was surprised to be told that my blood pressure was high (149/95 the first time) and it took a number of years, but I've brought it down under 120/80 without resorting to any meds. It improved part way fairly quickly, then I couldn't seem to improve it for a very long time until it suddenly dropped again, so don't be discouraged by plateaus or setbacks along the way. Stay focussed and I think you'll meet your goals.