Benign paroxysmal positional vertigo (BPPV) is the most common cause of disequilibrium overall. This disease happens when tiny crystals in the inner ear break loose and get into other parts of the inner ear (where they do not belong). Patients with BPPV usually have episodes of spinning disequilibrium triggered by various head movements, such as rolling over in bed, or tilting the head backward or forward. A physician or vestibular physical therapist can often can figure out whether a patient has BPPV by examining the person’s eye movements, though sometimes this examination needs to be repeated over time because of the episodic nature of BPPV. BPPV is treated with a variety of physical therapy maneuvers. BPPV is not treated with medication or surgery. Even when treated well, BPPV often recurs, and there is not yet any known way of preventing this.