Up till now, the only major way of assessing pain is to ask people what they are feeling.
However, a series of studies involving brain imaging techniques such as functional magnetic resonance imaging (fMRI) has changed history, as distinct differences between the brains of people in pain and others who are not have been shown.
"Pain seems to increase the blood flow to certain parts of the brain, roughly in proportion to the amount of pain felt, and we can measure that activation in a brain scan," The Times quoted Irene Tracey, professor of anaesthetic science at Oxford University and director of its centre for fMRI and the brain, as saying.
The findings suggest that pain could one day be measured objectively.
Tracey described her research at the Cheltenham science festival.