Definition
A short-lived sensation of spinning or tilting caused by unequal pressure between the two middle ears, typically occurring during a rapid change in altitude when one ear equalizes faster than the other.
Plain English
A brief dizzy spell that happens when the air pressure inside one ear changes faster than the other, usually while climbing or descending.
Context Anchor
Encountered in aeromedical, altitude-change, and spatial disorientation discussions, especially during climbs, descents, or flight with a cold or blocked ears.
Derivation
From Latin alter (other) and baros (pressure), plus vertigo (a turning or whirling). Literally 'dizziness from differing pressures' — a useful clue that the cause is a pressure mismatch between the two ears, not a balance problem in the brain.
Why Pilots Care
It produces sudden, unexpected disorientation that can impair aircraft control during takeoff, climb, or approach.
Analogy
It is like having one ear pop before the other during an elevator ride or airline descent, except the uneven ear pressure also affects your sense of balance and can make the world feel like it is turning.
Grounding Statement
Picture descending with a blocked ear: one ear clears, the other does not, and for a moment your body may report a turn that is not actually happening.
Intuition Check
Alternobaric vertigo is not fear of heights and not ordinary dizziness from looking down. It is a balance sensation caused by unequal pressure between the ears.
Example Sentence 1
The pilot felt a brief spinning sensation during a fast descent and recognized it as alternobaric vertigo caused by one ear clearing slower than the other.
Example Sentence 2
Rapid climbs without ear clearing can trigger alternobaric vertigo and momentary loss of orientation.