University of Michigan, USA
We are beginning to better understand the mechanisms that underlie the transition from acute to chronic pain. As with many other complex chronic diseases, although chronic pain runs strongly in families, there are no single genes that confer strong effects, so at present this risk is thought to be polygenic with likely epigenetic factors playing a significant role. Other risk factors for developing chronic pain include female sex, previous chronic pain elsewhere, a history of trauma or stress, a history of mood or sleep problems, and cognitions such as catastrophizing. Biological mechanisms that may contribute include altered pain and sensory processing on quantitative sensory testing, changes in brain connectivity patterns, structure, or neurochemistry on functional neuroimaging, and a primed immune system.