What causes it
The inner ear contains crystals of calcium carbonate that sit in a gel layer and help detect gravity and movement. If some break free, usually with age, after a head knock, or for no clear reason, they can drift into a semicircular canal, which detects rotation. There they move with gravity when the head changes position and send a false signal that the head is spinning.
What it feels like
Short bursts of spinning vertigo, usually lasting less than a minute, triggered by specific movements: turning over in bed, lying down or sitting up, looking up to a high shelf, bending forward. Between episodes there may be mild unsteadiness or a sense of being off. Nausea is common. Hearing is not affected. Symptoms often start suddenly on waking.
How it is diagnosed
A positional test, usually the Dix-Hallpike, in which the head is moved into the triggering position while the examiner watches for a characteristic eye movement. This identifies which ear and which canal are involved, and no scan is needed in a typical case.
How it is treated
A repositioning manoeuvre, most commonly the Epley, moves the head through a sequence of positions that let gravity carry the crystals back out of the canal. It takes a few minutes, may provoke vertigo during the sequence, and resolves BPPV in around 80 per cent of people after one session and most of the rest after a second. Recurrence happens in some people and is treated the same way.
What does not work
Medication for dizziness does not move the crystals. Waiting sometimes works, over weeks, but treatment is quick.
At Omnia
Vestibular First at our Chiswick clinic assesses for BPPV and treats it in the same session where it is found.