What causes chronic limb pain after amputation?

Phantom pain: The brain does not necessarily adapt to amputation, and may persist in sensing limb presence, and harm to limb even though gone. This creates a painful feedback loop with neurogenic central pain reactions. Can be handled with nerve pain suppressant meds such as lyrica, (pregabalin) gabapentin, amitryptiline, cymbalta, etc.

Nerves: Phantom pains occurs after an amputation and is related to the nerves being cut during the amputation. It is unclear exactly why they occur but one of the possibilities is that the brain "memorized" the pain so it is still present even when the part of the body is removed. It usually improves with time after an amputation. If it does not meds to treat nerve pain are helpful.