Pain is a signal from the central nervous system indicating that something is wrong. Pain can be differentiated in various ways, including how long it has been occuring: acute pain versus chronic pain.

Phantom limb pain is pain coming from a part of the body that is no longer there. It typically occurs with amputations, after the pain from surgery has gone. It is not a feeling that the limb or amputated tissue is still there, but pain from it the limb or amputated tissue.