A sudden spin when rolling over in bed can feel alarming, especially when it comes out of nowhere. One moment you are turning your head, the next the room seems to whirl for a few seconds. One of the most common reasons for this pattern is Benign Paroxysmal Positional Vertigo, better known as BPPV. BPPV is not usually dangerous, but it can be unsettling. It can affect confidence, sleep, balance, driving, work and day-to-day movement. The good news is that it is often very treatable,...