A report in the latest edition of the New England Journal of Medicine says that doctors have uncovered how to "see" pain on brain scans.
The study, which was undertaken by doctors at the University of Colorado and several other institutions, can also tell whether or not drugs or medicine are actually helping relieve the pain.
By discerning the difference between painful heat and non-painful warmth on brain scans, the research was able to observe marked differences in the signatures.
Doctors hope that in the future, these scans could be used to determine what is causing pain in small children and infants, people with mental illness and people who are unable to talk.
You can check out more on the study in the New England Journal of Medicine.