I had a stress test and passed in November, my BP when checked on Aug. 16 was 164/90. My doctor recommended either 1 hour exercise of walking or equivalent 5 days per week, or go on meds. I chose the exercise, and I found that I get dizzy after about 1/2 hour, and when mowing grass behind a push mower, I get dizzy and started to get nausea. These things went away after I rested. Can high blood pressure alone cause this or is there other factors?