Scans have shown people who find the sounds of chewing or breathing unbearable have a genuine brain abnormality, scientists have found.
While many people find hearing people eat off-putting or pen clicking annoying, others who suffer from misophonia report feeling disgust when exposed to the noises.
Referring to "trigger sounds", people with misophonia can respond with an intense "fight or flight" reaction.
Now researchers at Newcastle University have reported finding a difference in the frontal lobe in misophonia sufferers, suggesting it is a genuine condition where medical opinion in the past has been sceptical.
Writing in the journal Current Biology, they found changes in the brain activity when a trigger sound is experienced.
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They also found people with misophonia experienced an increased heart rate and sweated when they were confronted by a trigger sound.
Researchers found a difference in the "emotional control mechanism" that causes their brains to go into overdrive on hearing trigger sounds.
Dr Sukhbinder Kumar, from the Institute of Neuroscience at Newcastle University, said: "For many people with misophonia, this will come as welcome news as for the first time we have demonstrated a difference in brain structure and function in sufferers.
"This study demonstrates the critical brain changes as further evidence to convince a sceptical medical community that this is a genuine disorder."
One misophonia sufferer said her GP laughed when she told him about her symptoms.
Olana Tansley-Hancock, 29, from Ashford in Kent, was eight years old when family meals became unbearable for her.
"The noise of my family eating forced me to retreat to my own bedroom for meals," she said.
"I can only describe it as a feeling of wanting to punch people in the face when I heard the noise of them eating - and anyone who knows me will say that doesn't sound like me."
