The thought of adding up the cost of presents, decorations and food for Christmas could be genuinely painful for more than half the population, researchers concluded.
Millions of people suffer from high levels of "maths anxiety". Brain scans of people waiting to carry out a maths test showed a higher than normal activity in the posterior insula, a region linked to physical and emotional discomfort.
There was no elevated level of activity when people actually carried out the numerical problems, suggesting that the pain was linked to nervous tension.
Dr Sian Beilock, of the University of Chicago, one of the study's authors, said that thinking about the cost of Christmas decorations, presents and food for a family gathering could potentially be enough to cause genuine pain for many people.
"People who are anxious about maths get nervous when they have to calculate a tip on a dinner bill when their friends are around, or are trying to understand newspaper polls about politics — anything where you have to add up in your head using maths can cause panic," she said. "This could even happen to people when they think about counting up the cost of Christmas.
"We showed that the more anxious people were about maths, the more they activated brain regions that we know are often involved when people experience pain or detect a threat."
The study, published in the Public Library of Science ONE journal, is the first to examine the impact of maths anxiety on the brain.
Previous research has shown that stressful experiences such as a divorce can cause physical pain.
For the latest study, researchers recruited 28 participants, half of whom said they were "very averse" to maths, and asked them how anxious they would feel about the prospect of 25 situations, including going to a maths lesson.
The team scanned volunteers' brains while they awaited instructions to carry out a maths test and detected a direct
link between maths anxiety and activity in the posterior insula. The connection disappeared when participants sat
Dr Ian Lyons, the co-author of the paper, said: "Anticipation is when you are really thinking about it, your mind is
racing and you are thinking about all
the things that could go wrong ... it is really about the psychological interpretation of it.
"This is a learned response — mathematics was invented only a thousand years ago so it seems extremely improbable that there would be some evolved fear in the same way that there is a fear of snakes or spiders.
"They can kill you, but maths cannot."
Dr Lyons added: "We need to be really sensitive to the context that can create maths anxiety."