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This is a medical emergency until proven otherwise.
It could be as simple as wax coating the ear drum.
However, the worst case scenario is sudden hearing loss.
This is presumed to be from painless inflammation, and would need immediate prednisone if there is a chance of saving the hearing.
Infection is another possibility.
In any case, immediate exam is needed.
A&E is recommended unless you can be in the doctors office now.
An ENT now would be ideal, but any of these options.
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