Benign paroxysmal positional vertigo, or BPPV, is an ear disorder that can cause a spinning sensation as you move your head. This disorder, which can be inconvenient but rarely serious, is thought to be related to stray bits of calcium in the inner ear. For a number of reasons, these crystals can move to other areas in the inner ear, where they may interfere with fluid. The brain receives confusing messages, and vertigo or dizziness results. Treatment involves a series of head movements done by a professional that repositions these crystals in an area where they will not cause trouble.