There are two theories for benign positional vertigo. The cupulithiasis theory implies that otoconia from the utricle become dislodged and irritate the cupula of the posterior semicircular canal. The canalithiasis theory implies that calcified deposits are found within the posterior semicircular canal. By their motion within the canal they create a force on the cupula that leads to vertigo. Various manuevers can be used to reposition these deposits into the utricle.