I had a dizzy spell last year a few days after getting back from vacation. It wasn't like vertigo with the room spinning and it wasn't like being light headed when you stand up too quickly, this was like being stumbling drunk. I had to hold on to a wall or I thought i was going to fall down. When it didn't get better in an hour or so went to the emergency room. They checked for heart attack, stroke and did a CT scan of my brain. They found nothing and the dizziness went away in a few hours. The ER dr suggested I see a neurologist.
First I saw an Ear, Nose and Throat dr to see if it was an inner ear issue. He ran a hearing test, a vertigo test, looked in my ears, asked me about the symptoms and said it wasn't an ear issue.
Next I saw a neurologist. He looked at the CT scan and said my brain looked normal for a 57 year old. He even asked what I do for a living. I said I'm an engineer and he said that makes sense, I have an engineer's brain

. He said my height (6'2") and ago (57) could be a problem as tall people have circulation issues. He did an EEG with things stuck all over my head and said it was normal. Then had an MRI done of my brain and he said it was normal. He gave me a vertigo drug to take if I got dizzy again. He said even though the ENT dr said I don't have a vertigo, if the drug makes me less dizzy, it's likely a neurological problem but if it makes me feel no change or worse, it's likely a heart issue. I took the drug next time I was dizzy and felt no change.
Finally I saw my cardiologist. He did a stress test, EKG and week long heart monitor sticker on my chest thing. Everything came back fine.
So now what? It only happens every month or so. I thought it could be hydration so I'm drinking more water but then I got dizzy again on Monday.