Pain is your body telling you that you have hurt it. This is a good thing, important when you are injured. It can also help diagnose problems with your body. Sometimes pain continues long after it's necessary. Amputees report phantom pain in the legs or arms they no longer have. There are different kinds of pain, and describing the type is useful in diagnosis: recurring, constant, steady, knife-like, radiating, sharp, dull. Medicines that dull pain are analgesics. Those that kill all feeling are anesthetics.