Your mind signals that you need to be aware that something with you physicaly isnt right and your brain send signals to make you aware which is what causes the pain, However on many occassions this is no longer required as the physical ailments have been repaired and have now fully recovered and the brain continues to send pain signals.
What we are doing here is reducing and at times fully removing the signals that are being sent and replacing them with comfort and soothing sensations.
We dont remove new pain as this is there for a reason, however old pain which is no longer needed can be replaced.