I am taking 20mgs. of Lisinopril and had no effects for the first...

I am taking 20mgs. of Lisinopril and had no effects for the first 84 days. My blood pressure has come down dramatically. It went from 200/110 to 128/74. Not bad !! However, on day 85, I walked across a parking lot with a piece of cardboard over my head for about 600 feet, to protect myself from the rain. I got into work and sat down at my computer and about one-half hour later I got extremely dizzy and started to faint. I got down on the floor and my arms and legs went numb, almost like my circulation system was shutting down. I thought I was going to black out and go into cardiac arrest. They rushed me to the hospital and checked me out all day. They did EKG's and checked my heart enzymes. All Good. Then I was given a stress test, which also checked out Good. I still felt rather weak, but was released anyway. The same event happened 8 days later, after cutting my dosage down to 10mgs. I was moving some pallets, holding them over my head again, and experienced another event very similar. It took about 1/2 hour to pass and for me to regain my composure. I think holding my arms over my head has either fluctuated my blood pressure, or I am cutting off the circulation up in the neck area. I have had a severe neck ache lately on the back right-side. The benefits outweigh the risks as far as my blood pressure, but if I pass out swimming, driving, trimming tree branches, etc and kill myself, it is of no longer a benefit. SO, I'M WARNING ALL OF YOU OUT THERE, TO TAKE HEED, AND BE CAREFUL WITH THE ACTIVITIES YOU PARTICIPATE IN. DELAY CERTAIN THINGS UNTIL YOU ARE OFF OF THIS MEDICATION, BUT DON'T STOP ON YOUR OWN. ALWAYS CHECK WITH YOUR PRIMARY PHYSICIAN FIRST.