Sarah Colwill, 35, has carried an English West Country accent her entire life but now sounds like she hails from the far east.
Ms Colwill believes her sudden accent shift can be traced back to one migraine attack that was so bad she had to be taken to hospital.
Doctors have reportedly told Ms Colwill she suffers from Foreign Accent Syndrome (FAS), an extremely rare condition with only a few recorded cases.
She said the changes in her speech were first noticed by the emergency services call operator.
It was funny at first but to think I'm stuck with this gets me down - my voice has begun to annoy me, she told The Mirror newspaper.
I'm having speech therapy but don't know if the Chinese accent will ever go away.
Ms Colwill, who has never been to China, said she was frustrated that many people often believed she was faking the accent.
The first recorded case of FAS was in 1941 when a Norwegian woman was struck by a piece of shrapnel and began talking with a German accent.
There are believed to be less than 20 people worldwide suffering from the condition.