Has anyone experienced this? My father is age 89 in a week. His blood pressure with medication is usually very controlled, but this past Tuesday it got very high. Systolic was 190, I don't remember the diastolic. Heart rate kept jumping around. We went to ER in the first hour the symptoms started presenting. It is two days later. With added medication his blood pressure is still high and he is still feeling dizziness. They wanted to send him home after finding no signs of heart attack or stroke or neurological damage other than unrelated neuropathy, but we asked for an MRI to check his ears and the veins in his neck and to make sure there aren't any bleeds. He isn't nauseated. Neurologist asked him to stand with his feet together and close his eyes, and he was unsteady on his feet when he did that.
I also was going to suggest a cardiac workup, including checking the carotid arteries.
There's also the possibility of vertigo.
My mom had vague symptoms like this. There were a laundry list of things going on, electrolyte imbalance, anxiety, ortho static hypotension, eventually congestive heart failure.
I hope someone will come along who has had a similar experience. I don't know where you are, but it is the middle of the night for most participants here.
Have you been to his PCP since the ER event? Do you have an appointment? The ER did their job in determining there was nothing apparent that needed immediate fixing. Now get Dad into the longer-term medical system for deeper analysis.