I m 56 years old and I have high blood pressure. I also take medication for it. The other day I was driving my car and had an episode that I have never experienced before. The feeling of extreme dizziness came on suddenly. I was not able to drive so I pulled over. It lasted about 10-15 seconds and then was over. I have had bouts of vertigo but this was nothing like that. After the episode I had no problems at all. Felt fine but very shook up. I did go to ER and later released. Needed to rule out stroke or heart attack. I am going to follow up with cardiologist. Do you have any idea what I was experiencing?