Sudden, short episodes of dizziness brought on by a change in the position of the head or body. Benign positional vertigo, also called benign paroxysmal positional vertigo (BPPV), results when small crystals of calcium carbonate collect within a part of the inner ear that is responsible for balance. In half of all cases, the cause is unknown. BPPV produces intermittent symptoms that may include light-headedness, loss of balance, and nausea in addition to dizziness. Rapid, involuntary eye movements may accompany the dizziness. Episodes of BPPV may appear intermittently for several weeks, disappear, and return again.