Chronic pain occurs when the back part of the Spinal Cord has been bombarded by severe pain for a long period of time. The Interneuron adjusts and transforms to the Wind-up Nerve by adding fast pain receptors that amplify the pain signal and pass the amplified signal to the the nerve tract that runs up to the brain. From there the thinking and emotional centers of the brain receive a large pain signal and the mind perceives increasingly severe intractable pain. Modifier Pathways in the brain attempt to tone down the pain, but are defeated at the back part of the spinal cord by the Wind-up Nerve. The brain keeps receiving amplified pain signals and the mind continues to perceive unrelenting and severe pain.