Canalith
Canalith
The manoeuvre worked. The spinning stopped, sometimes within a day, and it felt like the end of it. Then months later you roll over in bed and the ceiling slides again. This is a common experience, and it is not a sign that the first treatment failed.
In BPPV, small crystals that normally sit in one part of the inner ear have ended up in one of the fluid-filled canals that sense rotation. When you move your head, they move too, and the canal reports a spin that is not happening. Your eyes respond to that false report, and the room appears to move.
A repositioning manoeuvre works by using gravity and a sequence of head positions to walk those crystals back out of the canal into a chamber where they no longer disturb anything. When it works, it can work quickly, which is part of why it feels so decisive.
But look at what it addressed. It moved particles from a place where they cause trouble to a place where they do not. It did nothing about why they came loose in the first place, and nothing to stop more of them coming loose later. The mechanism that produced the problem is untouched by the thing that fixed the problem.
That is the whole explanation for recurrence, and it is worth holding onto, because the alternative interpretation — that the treatment did not really work, or that something is getting worse — is both discouraging and usually wrong.
Often there is no identifiable reason, and that is a legitimate answer rather than a gap in the explanation. Where a cause is recognised, the ones that come up are things that either disturb the inner ear mechanically or affect the structures the crystals sit in:
None of these is something you can undo retrospectively, and most are not things you would want to organise your life around avoiding.
When BPPV returns it often returns recognisably. The same trigger positions — rolling towards one side in bed, lying back, tipping the head up to a high shelf. The same short duration, seconds rather than minutes, settling when you stay still. Frequently the same ear.
That recognisability is genuinely useful. Someone who has been through it once tends to identify a recurrence far faster than they identified the first episode, which shortens the time spent wondering what is happening.
It is also why a record helps more than memory does. Which side, which movement, how long it lasted, how long the whole episode ran before it settled — written down at the time, not reconstructed weeks later in a waiting room. Anyone assessing a recurrence will ask exactly these questions, and "it was the left, I think, in about March" is a much weaker answer than a dated entry.
Tracking episodes is worth doing, with one caution: it is easy to find patterns in small numbers of events that are not really there. Two episodes in the same month after a quiet year may be coincidence. A change of season, a stressful fortnight and a recurrence may have nothing to do with one another.
What a record is genuinely good for is the boring, factual layer: how often, which side, which movements, how long each ran, and what happened afterwards. That is the material a clinician can use, and it is the part memory is worst at. Interpretation is their job; accurate raw material is the contribution you can make to it.
The most important thing a record does is make a change obvious. Vertigo that lasts hours rather than seconds, that no longer depends on a change of head position, that arrives with new hearing loss, or that simply does not resemble your previous episodes, is not more of the same thing — and it warrants assessment rather than another attempt at the manoeuvre that worked last time.
This article explains a mechanism; it is not medical advice and it is not a diagnosis. Several conditions cause vertigo and they cannot be told apart from a description on a website. See a clinician about new or recurring vertigo, and treat it as urgent — emergency care, the same day — if vertigo comes on suddenly together with any of: double vision, weakness or numbness on one side, trouble speaking or swallowing, a severe or unusual headache, difficulty walking or a new inability to stand, or new hearing loss in one ear.
Canalith is a vertigo and dizziness diary for iPhone and Apple Watch: log an episode with one drag of a dial, have the barometric pressure and weather recorded with it, follow the exercise your clinician prescribed, and export a one-page report for your appointment. It records and guides; it does not diagnose or treat. The app is not on the App Store yet — join the waitlist on the home page.