I had bouts of positional vertigo for several years, often very severely, when my mother sent me a newspaper article on how to prevent it. The main thing is to avoid leaning your head backwards and down, like into the shampoo bowl at the hair salon. When I stopped doing this, vertigo stopped. I also won't let the dentist put me too far backwards with head down in the chair, or I don't paint ceilings, for example. It has worked. Thanks for letting me share this. Vertigo is no fun.