Pain can be felt without tissue damage

Activity in the neurons that responds to injury is called nociception. It allows us to recognise and label different kinds of damaging stimuli, such as slamming your hand in the door or burning it on a stove.

Researchers wanted to observe what happens in the brain when we're exposed to damaging stimuli. They reported a pattern of neural activation across a network of brain regions that tracked nociceptive activity. Surprisingly, neuroscientists also observed this signature in the brain, and patients can report intense pain, without any tissue damage.