Chronic pain explained: central nervous system hypersensitization
Here is an excellent article that helps explain chronic pain. The central nervous system (CNS–brain and spinal cord) can become “hypersensitized” following an injury, trauma, and/or period of chronic or severe stress, in ways that perpetuate, exacerbate, or distort pain, both from any initial injury, but also from normally trivial or benign sensations, such as light touch, massage, or exercise, […]