BPPV

Benign paroxysmal positional vertigo (BPPV) is a mechanical disorder of the peripheral vestibular system. Tiny calcium-carbonate particles, called otoconia, become dislodged from the utricle and enter a semicircular canal. The posterior canal is involved most often. When the patient turns the head, the particles shift through the canal fluid and abnormally deflect the cupula. The brain receives a false signal that the head is rotating, while vision and proprioception report a different position. That sensory mismatch feels like spinning. The particles stop moving once the head is still, so the vertigo is intense but brief—typically less than one minute. Rolling over in bed, looking up, bending forward, or extending the neck may trigger another episode because each movement makes the particles shift again. The short, reproducible relationship between a particular head movement and the onset of spinning is the pattern an experienced nurse notices first. BPPV does not usually cause continuous spontaneous vertigo, focal neurological deficits, or hearing loss. The term benign describes the usual peripheral mechanism; it does not make every report of dizziness safe to dismiss.