Deborah Reed lived in a tall historic house on a tree-lined street in tony northwest Portland, Ore. In 2003 the author and mother of two boys developed deep muscle pain and profound fatigue, seemingly out of nowhere. “I remember climbing the wood stairs to my bedroom on the third floor,” Reed recalls. “It was agonizing.” Reed would spend entire days in her bed, getting up only for trips to the bathroom. When the pain was at its worst, she once went 10 days without leaving her bedroom.