How does ‘phantom pain’ work? Is it due to your nerves or something in your brain? Why/how do amputees still feel the limb after it is gone?
Phantom limb: the neural pathways are still in the brain and spinal column and fire sometimes, causing it to feel like the limb is still there.
Phantom pain: when the brain and spinal column are confused about why the limb isn’t there anymore, the easiest way for them to cope with it is to trigger the pain response because it’s the easiest sensation to make.
Here ya go: https://www.mayoclinic.org/diseases-conditions/phantom-pain/symptoms-causes/syc-20376272
If we fully understood what was going on then we might be able to prevent it from happening but alas we have very little understanding of the details of our brain. We do know that part of the brain is used for “sensing” where all the limbs are at all times. This is why you are able to move your hands very precisely without looking at them. And it kind of looks like this part of your brain does not change when you lose a limb. As for pain the brain have to interpret a lot of thing as pain which is not directly triggering the pain receptables. It is not that uncommon for damage to cut the neurons which sends the pain signal to the brain and the brain will therefore be unable to feel any pain directly. So the brain will make its own pain signals when it realizes. And this might be the case with long time amputations as well as the brain looks as if it is unable to turn off this feature for the missing limb or at least that it will randomly turn itself on at regular intervals.
Your brain still registers your limb nerves as being as long as your limb, so it has trouble gauging the new distance of your nerves.