Book excerpt: About 100 million Americans live with some form of chronic pain—more than the combined number who suffer from diabetes, heart disease, and cancer. But chronic pain has always been a mystery. It often returns at the slightest provocation, even when doctors can't find anything wrong. Oddly enough, whether the pain is physical or emotional, traumatic or slight, our brains register all pain as the same thing, and these signals can keep firing in the nervous system for months, even years. In Total Recovery, Dr. Gary Kaplan argues that we've been thinking about disease all wrong. Drawing on dramatic patient stories and cutting-edge research, the book reveals that chronic physical and emotional pain are two sides of the same coin. New discoveries show that disease is not the result of a single event but an accumulation of traumas. Every injury, every infection, every toxin, and every emotional blow generates the same reaction: inflammation, activated by tiny cells in the brain, called microglia. Turned on too often from too many assaults, it can have a devastating cumulative effect. Conventional treatment for these conditions is focused on symptoms, not causes, and can leave patients locked into a lifetime of pain and suffering. Dr. Kaplan's unified theory of chronic pain and depression helps us understand not only the cause of these conditions but also the issues we must address to create a pathway to healing. With this revolutionary new framework in place, we have been given the keys to recover.