Do those things happen in short bursts or flashes or more like hrs and days?

I had some weird quick dizzy "spells" that lengthened in time lasting up to an hour or so over a week and a half. { back in spring of 05}
as the spells progressed I would get a fast heart rate along with it.
a couple of times it got scary.

so I finally went to a naturopath and she did full blood work and full physical/neuro check- all ok.
and when it was time for a second follow up- all my sx of that had vanished, so i called and told her - she surmised that it was just a very odd virus of some sort.