Pain remains a poorly understood and managed symptom. A limited mechanistic understanding of interindividual differences in pain and analgesia response shapes current approaches to assessment and treatment. Opportunities exist to improve pain care through increased understanding of how dynamic epigenomic remodeling shapes injury, illness, pain, and treatment response. Tightly regulated alterations of the DNA-histone chromatin complex enable cells to control transcription, replication, gene expression, and protein production. Pathological alterations to chromatin shape the ability of the cell to respond to physiologic and environmental cues leading to disease and reduced treatment effectiveness. This review provides an overview of critical epigenetic processes shaping pathology and pain, highlights current research support for the role of epigenomic modification in the development of chronic pain, and summarizes the therapeutic potential to alter epigenetic processes to improve health outcomes. 1. Introduction Pain is the number one reason patients consult a health care provider in the United States, with one in every three emergency room patients and more than 60% of all primary care patients listing pain as their chief complaint [1]. Chronic pain, including migraine headaches and low back pain, affects more than 250 million Americans and nearly 10% of the world’s population. The incremental health care and societal costs of undermanaged pain range from $560 to $635 billion annually in the United States, including lost worker productivity and the impact of addiction, with another $900 billion worldwide [1–4]. Pain, however, remains a poorly understood symptom. No person experiences pain like any other and even the same person may experience pain in different ways, at different times, and under different circumstances challenging both assessment and treatment. Without a clear understanding and consensus as to the mechanisms underlying these differences, nurses are limited in their ability to develop an evidence-based intervention science to guide symptom management. The incorporation of genetic approaches into nursing and multidisciplinary research has been one of the most significant research developments in the last 10 years, providing new and promising opportunities to understand interindividual differences in pain and therapeutic response. Pain genetics is a broad term that describes both classic Mendelian techniques used to identify inherited variation in pain sensitivity and analgesic response as well as newer gene-level DNA and RNA sequence
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