While a little heavy, it is not written for specialists and well worth a look.
TL;DR: Chronic pain has long thought to be due to the way your brain perceives pain signals, but recent research has indicated abnormal peripheral (rather than central) nerve and immune activity may contribute to some types of chronic pain. This may give us new ways to treat these conditions.
By the way, if you do not yet read The Conversation give it a look. It is a forum where the contributors are drawn from the fields about which they talk. Teachers, scientists, researchers, academics etc. all write topical pieces in which they give an expert perspective on current affairs and developments. Authors must disclose all funding and conflicts of interest.