Hi Dennis,
So sorry you had vertigo, it's the worst. There's something about being totally convined that you're tumbling through space and knowing at the same time that you can't possibly be tumbling through space that is SO disconcerting. Vertigo was my main symptom pre-diagnosis, and it's been an off and on challenge since treatment. Hate it.
To answer your question about vertigo being triggered by a certain position, the answer is yes. At one time, my vertigo was triggered by rolling over in my sleep. These days it's triggered when I bend over to shovel snow or dirt. You'll want to talk to your doctor of course, because vertigo is a complicated symptom. In the meantime, as soon as you think something is happening, try to get to a safe place to wait it out. For me, "vertigo falls" are like being pulled down, and I'm more likely to get hurt.
If you're having other balance issues, Pat is right, Vestibular Therapy can work wonders, and after an initial session or two, it can be done at home. Saves a co-payment, eh?
Good luck...I hope the vertigo was just a bump in the road of your recovery and that you never experience it again.
Betsy