Interesting.

"Experiments show that being dumped by a lover activates brain regions more usually associated with processing physical pain, such as the searing sensation of being burnt. In other words, a broken heart really does hurt. The finding could help explain why being given the heave-ho can be so painful for so long.

The intriguing idea comes from an American study of 40 men and women whose relationships had ended against their wishes. All said the experience left them deeply hurt.
Their brains were scanned as they looked at various pictures. They rated looking at the picture of an ex and being touched with a hot probe as more painful than thinking about a friend or being touched with a cooler probe.
More interestingly, they said that break-up thoughts hurt as much as the hot probe. Analysis of the scans revealed that the same brain regions lit up when processing the two types of pain, the journal Proceedings of the National Academy of Sciences reports.
'On the surface, spilling a hot cup of coffee on yourself and thinking about how rejected you feel when you look at the picture of a person that you recently experienced an unwanted break up with may seem to elicit very different types of pain. But this research shows that they may be even more similar than initially thought.'
Other research has shed light on why we often yearn to get back together with a lost love.
Brain scans of men and women pining for a past partner revealed that a broken heart triggers the same feeling in the brain as kicking a drug addiction. But there is hope for the lovelorn.
The study showed that the greater then number of days since the rejection, the less activity there was in the parts of the brain behind emotional attachment."